Homebrewers Association | AHA Forum

General Category => Yeast and Fermentation => Topic started by: S. cerevisiae on July 11, 2014, 11:51:36 PM

Title: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 11, 2014, 11:51:36 PM
A yeast culture "owns" a batch of wort by shutting out competitors.  It rapidly consumes dissolved oxygen, which shuts out aerobic microorganisms.  A yeast culture also lowers the pH of the medium from around 5.2 to around 4.2, which shuts out pH sensitive anaerobic microflora.  The final defense that a yeast culture mounts is the production of ethanol, which is toxic to microorganisms, including the culture itself.

Replacing green beer with boiled water strips the culture of the force field that it built for itself, which means that the water has to be completely free of wild vegetative cells (and spores that can germinate into vegetative cells) because they will feast on dead yeast cells.   Bacteria cells multiply three times faster than yeast cells (i.e, an eight-fold increase in bacteria cell count for every two-fold increase in the yeast cell count), which means that a small infection can overtake a larger yeast culture when pitched into fresh wort.

The best way to crop is to "top crop" at high krausen.  However, top-cropping requires one to use a true top-cropping strain in order to be most effective.   Top-cropping naturally purifies a culture because wild yeast and bacteria do not floc to the top.  Top-cropped yeast can be repitched almost indefinitely.

When using a non-top-cropping yeast strain, I usually leave enough liquid behind after racking to be able to swirl the solids back into suspension (my primary volume is 1/3 to 1/2  gallon larger than the volume  I expect to rack).  Swirling the solids back into solution using green beer, waiting a few minutes for the heaviest fraction to settle, and then decanting the liquid fraction has the same effect as rinsing with boiled water; however, it keeps the low pH, ethanol laden environment intact.   If one wants to attempt to rid the culture of mutants, one can decant and discard most of the supernatant (liquid above the solids) as soon as a creamy layer of yeast forms on the bottom of the container.

As stated above, one of the first things that a yeast culture does when pitched into a batch of wort is to lower the pH from around 5.2 to around 4.2.  One has heard that pathogens do not grow in beer.  One of the reasons why pathogens do not grow in beer is due to its relatively low pH.  For example, Clostridium botulin growth is inhibited below pH 4.6.

Contrary to what was written in early amateur brewing books, brewing yeast cultures do not respire in wort due to a phenomenon known as the Crabtree effect.  Hence, brewing yeasts do not go through a period of respirative (aerobic) growth before they start to reproduce fermentatively (anaerobic growth).  In the presence of glucose levels above the Crabtree threshold, all reproduction is fermentative.  As many of you probably noticed while reading Yeast, yeast cells use dissolved oxygen to  build ergosterol and unsaturated fatty acid (UFA) reserves (these reserves are shared with with all of the daughter cells).  Yeast cells perform this feat by shunting oxygen to the respirative metabolic pathway while simultaneously metabolizing the carbon source via the fermentative  metabolic pathway.

What this preference to reproduce fermentatively means to a brewer is that yeast cells pretty much start producing ethanol almost as soon as they are pitched into a batch of wort.  While ethanol has a limiting effect on the viability of a yeast culture, it also protects the culture from infection.  Boiled water is not truly sterile.  Boiled tap water also tends to have a pH of at least 7.0; therefore, it raises the pH of the culture.

With the above said, most experienced amateur brewers eventually reach the conclusion that one can just crop and repitch without doing anything to separate the viable cells from the dead cells and break material, especially if they leave most of the break and hop material in the kettle.   Less is definitely more when cropping yeast.

(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/YeastCrops_zps33da0025.jpg)
Title: Re: Just say "no" to yeast rinsing
Post by: chumley on July 12, 2014, 01:22:04 AM
Excellent post.  I have been brewing since 1990, and I never bought into the rinsing hooey.  And, my beers all attenuate well and are excellent.

Why add silly extra steps to the process?  KISS
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 12, 2014, 02:04:26 AM
KISS indeed!
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 12, 2014, 02:18:39 AM
By the way, here is an interesting publication that I found on the Fermentis website this evening: http://www.fermentis.com/wp-content/uploads/2010/07/2010_TT_EN_HD.pdf


"Recovering yeast after fermentation and repitching

Recovering yeast after fermentation and repitching is possible if the cell count is controlled to give the correct yeast pitching levels. In order to control them, laboratory equipment will be needed. In the same way and using the same equipment, bacteria can be removed by acid washing in carefully controlled conditions. In case of repitching, yeast must not be stored out of beer for long periods, even at low temperatures, as yeast glycogen levels will fall causing slow fermentations.

Yeast mutation occurs rapidly in brewing environments, repitching can be a delicate operation and may cause beer quality problems in terms of flavour, yeast settling, diacetyl absorption. Effects of repitching can be seen in as few as 3 to 5 brews especially concerning diacetyl reabsorption. For ale beers that are generally more flavoursome diacetyl levels are less critical."



Title: Re: Just say "no" to yeast rinsing
Post by: erockrph on July 12, 2014, 02:28:12 AM
Great info. One of the reasons I was hesitant as a newbie to reuse yeast was I thought I was doing it wrong (or at the very least, half-assing it) by not washing my yeast. Now my only reason is that I don't want to catch s*** from my wife for all the mason jars in the fridge.
Title: Re: Just say "no" to yeast rinsing
Post by: quattlebaum on July 12, 2014, 02:29:14 AM
S. Cerevisiae i really enjoy your post! Very educational truly appreciated ;D
Title: Re: Just say "no" to yeast rinsing
Post by: Joe Sr. on July 12, 2014, 02:41:14 AM
I didn't read your post.  It's far too long for my attention span this evening.

I like the Old Rasputin in your fridge, though.  You get props for that.

Between that and the subject line, I think I got all I need to know.

I've never bothered rinsing yeast, and I don't see any reason to start.  Stay with what works.
Title: Re: Just say "no" to yeast rinsing
Post by: Jeff M on July 12, 2014, 02:14:27 PM
I rinsed ~1 cup of slurry with 2~ cups of autoclaved(15 min at 15PSI in a pressure cooker) water about a week ago.  do you think using this is a bad idea?  Its a first gen slurry.

Jeff
Title: Re: Just say "no" to yeast rinsing
Post by: Kinetic on July 12, 2014, 05:10:16 PM
I like the concept of re-using yeast.  Saving money on yeast is fiscally responsible.  The results are good and can even be subjectively better than the first pitch depending on your preferred taste.

However, I tend to prefer a different yeast on the next batch and use a wide variety of yeasts.  It may be 3-5 months before I get a hankering for the same yeast, so I rarely harvest and re-use yeast.  If I did, I could save maybe $20 a year.  Not really worth the risk or effort to me.  Keeping a proper yeast bank with multiple strains is more effort than I'm willing to provide.

Occasionally, when I want to use the same yeast twice in a row, I'll make a double sized starter and split it in half.  Use one half immediately and save the other for the next batch.  That seems to work well for me.   
Title: Re: Just say "no" to yeast rinsing
Post by: erockrph on July 12, 2014, 06:25:34 PM


Occasionally, when I want to use the same yeast twice in a row, I'll make a double sized starter and split it in half.  Use one half immediately and save the other for the next batch.  That seems to work well for me.   

I do this pretty often when I actually need a starter (which is generally just for lagers, since I brew 3 gallon batches). I figure if I'm growing a pitch I might as well make enough for two beers.

So, question to the yeast experts in the audience - how long would you say is too long to hold on to some yeast slurry under beer in the fridge I'd you're planning on making a starter with it prior to pitching?
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 12, 2014, 09:40:03 PM
I rinsed ~1 cup of slurry with 2~ cups of autoclaved(15 min at 15PSI in a pressure cooker) water about a week ago.  do you think using this is a bad idea?  Its a first gen slurry.

I personally believe that that yeast rinsing serves no useful purpose.
Title: Re: Just say "no" to yeast rinsing
Post by: ynotbrusum on July 13, 2014, 01:30:20 PM
I rinsed ~1 cup of slurry with 2~ cups of autoclaved(15 min at 15PSI in a pressure cooker) water about a week ago.  do you think using this is a bad idea?  Its a first gen slurry.

I personally believe that that yeast rinsing serves no useful purpose.

Agreed.  I just repitch slurries and let the yeast sort it out, figuring that in most fights at the microbe level the yeast will win.  Be sanitary, of course, but let them stay in beer and don't mess with them otherwise.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on July 13, 2014, 02:55:44 PM
I rinsed ~1 cup of slurry with 2~ cups of autoclaved(15 min at 15PSI in a pressure cooker) water about a week ago.  do you think using this is a bad idea?  Its a first gen slurry.

I personally believe that that yeast rinsing serves no useful purpose.

My experience with rinsing and not rinsing agrees with you.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 13, 2014, 03:20:54 PM
So, question to the yeast experts in the audience - how long would you say is too long to hold on to some yeast slurry under beer in the fridge I'd you're planning on making a starter with it prior to pitching?

Viability is strain and storage temperature dependent.   It comes down to how fast the cells exhaust their glycogen reserves.  A yeast crop will last a long time if one feeds it fresh wort every three to four weeks.  Some strains will last several months to a year or more without doing anything.  Granted, viability will drop over time, but there are a lot of yeast cells in 150 to 200 milliliters of slurry.   

I propagated a culture from a bottle of Tupper's Hop Pocket back in the nineties.   I repitched that culture every three to four weeks through the spring and summer.  The final crop sat in my refrigerator undisturbed until April of the following year.  I was about to discard it when a brewer that I knew at the time asked if he could have it.  I suggested making a starter, but he pitched the crop straight into a 5-gallon batch after decanting the supernatant.  I was astonished at how well it performed. 
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on July 13, 2014, 03:45:14 PM
I used to "rinse" my yeast for repitching. Then I tried a slightly different method after listening to a Brew Strong episode on rinsing. I saw very little difference in the final product.

For the last few batches ive left a half inch or so of beer on the yeast, swirl it up good,  and pour into a sanitized 2 qt jar. I can't say that the final results are drastically better but its much easier and makes sense as a happy place for yeast to store short term.

I have a chunk of wy1084 in the fridge from an irish dry stout I brewed several months ago. I'm tempted to toss it but im going to let it sit till next year and pitch it just to see how well it does.
Title: Re: Just say "no" to yeast rinsing
Post by: mattybrass on July 14, 2014, 03:52:53 PM
I rinsed ~1 cup of slurry with 2~ cups of autoclaved(15 min at 15PSI in a pressure cooker) water about a week ago.  do you think using this is a bad idea?  Its a first gen slurry.

I personally believe that that yeast rinsing serves no useful purpose.

My experience with rinsing and not rinsing agrees with you.

Instead of rinsing the yeast after racking off the beer, what do you both recommend that we do? (Denny & Cerevisiae)
Title: Re: Just say "no" to yeast rinsing
Post by: morticaixavier on July 14, 2014, 03:54:31 PM
I rinsed ~1 cup of slurry with 2~ cups of autoclaved(15 min at 15PSI in a pressure cooker) water about a week ago.  do you think using this is a bad idea?  Its a first gen slurry.

I personally believe that that yeast rinsing serves no useful purpose.

My experience with rinsing and not rinsing agrees with you.

Instead of rinsing the yeast after racking off the beer, what do you both recommend that we do? (Denny & Cerevisiae)

don't rinse it.  ;) seriously though, if you have another beer to pitch into do that, if you don't, fill a mason jar or plastic jar or bucket with a tight fitting lid that you have sanitized before hand. Leave it under beer until you are ready to pitch it or make a new starter with it.
Title: Re: Just say "no" to yeast rinsing
Post by: bluesman on July 14, 2014, 04:34:53 PM
Very interesting post and thread. I've rinsed yeast as a standard practice when time permits, and I've re-pitched direct from a previous batch (without rinsing) many, many times as well. Honestly, I haven't noticed a marked difference in beer quality, although I haven't blind taste tested this in practice either. You make a great case for "not rinsing" yeast". Thanks for posting.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on July 14, 2014, 04:49:16 PM
Instead of rinsing the yeast after racking off the beer, what do you both recommend that we do? (Denny & Cerevisiae)

I just leave a bit of beer behind in the fermenter, swirl up the yeast, trub, and beer and pour it all into a sanitized container.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on July 14, 2014, 04:51:07 PM
don't rinse it.  ;) seriously though, if you have another beer to pitch into do that, if you don't, fill a mason jar or plastic jar or bucket with a tight fitting lid that you have sanitized before hand. Leave it under beer until you are ready to pitch it or make a new starter with it.

You don't want to screw the lid on too tight, especially if it's a glass jar.  I've seen too many pics of jars that have exploded on the fridge.  Even refrigerated, the yeast will keep producing CO2.  That's why I use plastic tubs with snap on lids.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 14, 2014, 05:23:54 PM
Instead of rinsing the yeast after racking off the beer, what do you both recommend that we do? (Denny & Cerevisiae)

As Jonathan already mentioned, you do not have to do a thing to cropped yeast in order to be able to re-pitch it.  Brewers have cropped and re-pitched yeast (barm) for millennia without rinsing it with boiled water.  In fact, all of the non-wild brewing cultures that we use today are the result of continuous cropping, especially true top-cropping strains.  If one finds a true top-cropper in a container of wort that was known to be absolutely sterile when placed outdoors, one can pretty much be assured that the yeast strain was left behind by another human.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 14, 2014, 05:42:14 PM
I just leave a bit of beer behind in the fermenter, swirl up the yeast, trub, and beer and pour it all into a sanitized container.

This technique is used by every truly experienced brewer that I know.   
Title: Re: Just say "no" to yeast rinsing
Post by: morticaixavier on July 14, 2014, 07:27:00 PM
don't rinse it.  ;) seriously though, if you have another beer to pitch into do that, if you don't, fill a mason jar or plastic jar or bucket with a tight fitting lid that you have sanitized before hand. Leave it under beer until you are ready to pitch it or make a new starter with it.

You don't want to screw the lid on too tight, especially if it's a glass jar.  I've seen too many pics of jars that have exploded on the fridge.  Even refrigerated, the yeast will keep producing CO2.  That's why I use plastic tubs with snap on lids.

true. I've found with mason jars with the two piece lid if too much pressure builds up the seal fails before the bottle but better safe than sorry.
Title: Re: Just say "no" to yeast rinsing
Post by: Stevie on July 14, 2014, 07:27:40 PM
true. I've found with mason jars with the two piece lid if too much pressure builds up the seal fails before the bottle but better safe than sorry.


I always seal "fingertip tight"
Title: Re: Just say "no" to yeast rinsing
Post by: HoosierBrew on July 14, 2014, 07:30:33 PM


true. I've found with mason jars with the two piece lid if too much pressure builds up the seal fails before the bottle but better safe than sorry.

+1.  The two piece lid definitely needs to be on loose.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 14, 2014, 08:16:19 PM
+1.  The two piece lid definitely needs to be on loose.

Which is why I store cropped yeast in 500ml Erlenmeyer flasks with #7 stoppers and airlocks.  A six-pack of Corning 4980 500ml Erlenmeyer flasks can be had for $25.25 shipped.  That's $4.21 per flask.  My oldest Corning 4980-500 is over twenty years old.

www.amazon.com/gp/offer-listing/B004XR5V0A/ref=dp_olp_new?ie=UTF8&condition=new
Title: Re: Just say "no" to yeast rinsing
Post by: chumley on July 14, 2014, 09:05:03 PM
I just leave a bit of beer behind in the fermenter, swirl up the yeast, trub, and beer and pour it all into a sanitized container.

This technique is used by every truly experienced brewer that I know.   

If it's thick, and I have siphoned most of the beer out of the fermenter, I will pour in a can of cheap swill like PBR (funny that I always seem to have cans of that lying around), then follow the rest of what Denny said.
Title: Re: Just say "no" to yeast rinsing
Post by: mattybrass on July 15, 2014, 12:52:17 AM

+1.  The two piece lid definitely needs to be on loose.

Which is why I store cropped yeast in 500ml Erlenmeyer flasks with #7 stoppers and airlocks.  A six-pack of Corning 4980 500ml Erlenmeyer flasks can be had for $25.25 shipped.  That's $4.21 per flask.  My oldest Corning 4980-500 is over twenty years old.

www.amazon.com/gp/offer-listing/B004XR5V0A/ref=dp_olp_new?ie=UTF8&condition=new

Denny too, would you say using flasks or mason jars are better? Also how would you recommend sanitizing them?


Sent from my iPhone using Tapatalk
Title: Re: Just say "no" to yeast rinsing
Post by: Jeff M on July 15, 2014, 01:12:18 AM
Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.
Title: Re: Just say "no" to yeast rinsing
Post by: Stevie on July 15, 2014, 01:38:46 AM

Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.

And please pretend, for at least some of us, that our microbiology education stopped at high school bio.
Title: Re: Just say "no" to yeast rinsing
Post by: dcb on July 15, 2014, 01:27:36 PM
Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.

+1.  I'm curious too.  I feel like I'm always on here asking naive, bone headed questions, but sometimes details that are obvious to you aren't at all obvious to a relatively new brewer who has been teaching himself from books and the internet.

One particular piece of this puzzle that drives me bat sh*t crazy is the question of what you guys do with all the break and fine dust from pellet hops when it comes to transferring from the kettle to the fermenter, and again when cropping yeast.  I'm starting to conclude that I'm being too dramatic trying to get clear wort out of the kettle.   I use hop bags to help me keep most of the pellet hop sludge out of the beer, but after the boil I still have quite a bit of break and fine hop dust left.  I've wasted quite a bit of beer trying to leave this stuff behind.

Then I read that guys like KlickitatJim put all their hops in commando, and it sounds to me like anything the whirlpool doesn't drop out goes unceremoniously into the kettle guts, feathers, and all.   Same for cropping yeast-- just swirl up all the crap in the bottom of the bucket and don't sweat what's in there.    Do I really have that right?




Title: Re: Just say "no" to yeast rinsing
Post by: morticaixavier on July 15, 2014, 02:40:14 PM
Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.

+1.  I'm curious too.  I feel like I'm always on here asking naive, bone headed questions, but sometimes details that are obvious to you aren't at all obvious to a relatively new brewer who has been teaching himself from books and the internet.

One particular piece of this puzzle that drives me bat sh*t crazy is the question of what you guys do with all the break and fine dust from pellet hops when it comes to transferring from the kettle to the fermenter, and again when cropping yeast.  I'm starting to conclude that I'm being too dramatic trying to get clear wort out of the kettle.   I use hop bags to help me keep most of the pellet hop sludge out of the beer, but after the boil I still have quite a bit of break and fine hop dust left.  I've wasted quite a bit of beer trying to leave this stuff behind.

Then I read that guys like KlickitatJim put all their hops in commando, and it sounds to me like anything the whirlpool doesn't drop out goes unceremoniously into the kettle guts, feathers, and all.   Same for cropping yeast-- just swirl up all the crap in the bottom of the bucket and don't sweat what's in there.    Do I really have that right?

you got it. barley wants to be beer. we just have to help it along a bit.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on July 15, 2014, 02:44:47 PM
I just leave a bit of beer behind in the fermenter, swirl up the yeast, trub, and beer and pour it all into a sanitized container.

This technique is used by every truly experienced brewer that I know.

I think that at least for me it's a combination of laziness and effectiveness.  It's the easiest thing to do and it works as well as anything else I've tried.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on July 15, 2014, 02:48:14 PM

+1.  The two piece lid definitely needs to be on loose.

Which is why I store cropped yeast in 500ml Erlenmeyer flasks with #7 stoppers and airlocks.  A six-pack of Corning 4980 500ml Erlenmeyer flasks can be had for $25.25 shipped.  That's $4.21 per flask.  My oldest Corning 4980-500 is over twenty years old.

www.amazon.com/gp/offer-listing/B004XR5V0A/ref=dp_olp_new?ie=UTF8&condition=new

Denny too, would you say using flasks or mason jars are better? Also how would you recommend sanitizing them?


Sent from my iPhone using Tapatalk

IMO, neither.  My LHBS sells bulk extract in 1/2 gal. plastic tubs with snap on lids.  I buy a few of them and use them for yeast storage.    They're unbreakable and the lids will just pop up a bit if too much pressure builds.  I've been using them for 10+ years with no problems at all.  I sanitize with StarSan.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on July 15, 2014, 02:50:28 PM
One particular piece of this puzzle that drives me bat sh*t crazy is the question of what you guys do with all the break and fine dust from pellet hops when it comes to transferring from the kettle to the fermenter, and again when cropping yeast.  I'm starting to conclude that I'm being too dramatic trying to get clear wort out of the kettle.   I use hop bags to help me keep most of the pellet hop sludge out of the beer, but after the boil I still have quite a bit of break and fine hop dust left.  I've wasted quite a bit of beer trying to leave this stuff behind.

Then I read that guys like KlickitatJim put all their hops in commando, and it sounds to me like anything the whirlpool doesn't drop out goes unceremoniously into the kettle guts, feathers, and all.   Same for cropping yeast-- just swirl up all the crap in the bottom of the bucket and don't sweat what's in there.    Do I really have that right?

Yep, that's exactly what I do.  When I use whole hops, I use a bag so they don't go into the fermenter, but all the other trub does.  When I use pellets they go in lose, go through the pump and into the fermenter.  when I reuse the yeast they're still on there.  It just doesn't matter.
Title: Re: Just say "no" to yeast rinsing
Post by: bluesman on July 15, 2014, 04:37:11 PM
I just leave a bit of beer behind in the fermenter, swirl up the yeast, trub, and beer and pour it all into a sanitized container.

This technique is used by every truly experienced brewer that I know.

I think that at least for me it's a combination of laziness and effectiveness.  It's the easiest thing to do and it works as well as anything else I've tried.

If it's simpler and produces good results...then it's a viable process in my book. I've made dozens of beers using this technique with very good results.
Title: Re: Just say "no" to yeast rinsing
Post by: tommymorris on July 15, 2014, 05:08:33 PM


+1.  The two piece lid definitely needs to be on loose.

Which is why I store cropped yeast in 500ml Erlenmeyer flasks with #7 stoppers and airlocks.  A six-pack of Corning 4980 500ml Erlenmeyer flasks can be had for $25.25 shipped.  That's $4.21 per flask.  My oldest Corning 4980-500 is over twenty years old.

www.amazon.com/gp/offer-listing/B004XR5V0A/ref=dp_olp_new?ie=UTF8&condition=new

Denny too, would you say using flasks or mason jars are better? Also how would you recommend sanitizing them?


Sent from my iPhone using Tapatalk

IMO, neither.  My LHBS sells bulk extract in 1/2 gal. plastic tubs with snap on lids.  I buy a few of them and use them for yeast storage.    They're unbreakable and the lids will just pop up a bit if too much pressure builds.  I've been using them for 10+ years with no problems at all.  I sanitize with StarSan.

I use sanitized 2L soda bottles.


Sent from my iPhone using Tapatalk
Title: Re: Just say "no" to yeast rinsing
Post by: ynotbrusum on July 15, 2014, 07:04:54 PM
I use anything from plastic bags in Tupperware containers to mason jars to plastic tea or juice containers to wide mouth 2000ml Erlenmeyer flasks with a foil covering (all sanitized, of course), but my favorite is no container at all.  I time my racking from primary to coincide with my brewing day, so I just swirl and pour from a primary into oxygenated, chilled wort that is waiting for the pitch in another primary fermenter.  No muss, no fuss.  Of course don't pitch it all! Half of the slurry for lagers and a third for ales, if it is pretty fresh (less than a month or so in the primary).

Watch the number of generations, but I have gone over 20 generations with WLP 800 without incident (I just wanted to try new yeast for my standby lager).
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 15, 2014, 07:13:25 PM
Denny too, would you say using flasks or mason jars are better? Also how would you recommend sanitizing them?

I have used both types of containers, and I prefer to use flasks if they are available.  Using Mason jars became standard practice back in the early days of brewing because lab glassware was difficult to obtain.  Scientific equipment suppliers only shipped to labs.  The use of baby food jars for making slants and small volumes of canned sterile wort was also part of the "make do with what you can get" early amateur brewing  culture.  I used recycled, de-labeled 4oz baby food jars for autoclaving solid and liquid culturing media during my first ten years in the hobby.  I now use Corning 1395-100 100ml Pyrex media bottles, and I would never go back to using baby food jars.


(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/MediaBottles_zpseed0bf41.jpg)

(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/MediaBottle_zpsdff03f83.jpg)



Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 15, 2014, 07:48:16 PM
Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.

My bottom cropping technique is outlined in paragraph number four of the original post in this thread.  It's basically the same technique that Denny uses with a couple of twists. 

As I mentioned earlier in response to Denny's post, the core bottom cropping technique that Denny and I use is used by almost all experienced amateur brewers that I know.  We have been cropping this way for so long that we can hold a conversation and do it at the same time without spilling any of the crop. 

One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol (or 91% isopropyl alcohol if one is patient enough to allow it to flash off) before decanting any yeast culture (that includes starters and all steps in the starter process).  The pouring surface of a container holding a yeast culture should always be treated like it is contaminated.  Just as a nurse or doctor disinfects one's skin before injecting one with a syringe to ensure that the needle does not drag surface bacteria into the injection site, wiping the pouring surface of a container that contains a yeast culture  prevents the yeast culture from dragging any wild microflora that may be resting on the pouring surface into fresh media or wort.  It's a cheap insurance policy.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on July 15, 2014, 07:58:07 PM
One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol (or 91% isopropyl alcohol if one is patient enough to allow it to flash off) before decanting any yeast culture (that includes starters and all steps in the starter process).  The pouring surface of a container holding a yeast culture should always be treated like it is contaminated.  Just as a nurse or doctor disinfects one's skin before injecting one with a syringe to ensure that the needle does not drag surface bacteria into the injection site, wiping the pouring surface of a container that contains a yeast culture  prevents the yeast culture from dragging any wild microflora that may be resting on the pouring surface into fresh media or wort.  It's a cheap insurance policy.

I work on the assumption that if the beer I'm cropping from isn't infected, then the sanitation is good and I don't need to bother wiping down the rim of my bucket before I pour.  Hasn't failed in hundreds of times.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 16, 2014, 03:20:45 AM
I work on the assumption that if the beer I'm cropping from isn't infected, then the sanitation is good and I don't need to bother wiping down the rim of my bucket before I pour.  Hasn't failed in hundreds of times.

The rim of a bucket is covered by a lid that keeps house dust from settling on it.  However, I still wipe the rim on my bucket out of habit when cropping. I also use carboys and better bottles with stoppers and airlocks for primary fermentation.  The pouring surface is not protected from settling house dust in that situation.  House dust is a rich source of bacteria.
Title: Re: Just say "no" to yeast rinsing
Post by: ajk on July 16, 2014, 01:09:09 PM
One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol
What's your source for 95% ethanol?  Everclear?  Something lab-grade?
(or 91% isopropyl alcohol if one is patient enough to allow it to flash off)
How do you know how long to wait?  I just guess, but I'm never sure.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 16, 2014, 01:36:12 PM
What's your source for 95% ethanol?  Everclear?  Something lab-grade?

Everclear works well; however, its sale is banned in many states.

Quote
How do you know how long to wait?  I just guess, but I'm never sure.

I flame isopropyl off of glass, which is why I prefer to use borosilicate (Pyrex, Kimax) glassware for yeast storage.   I wait until the surface is visually dry on plastic. Ninety-one percent isopropyl flashes off quickly if applied lightly.  That's why I use it and not the garden variety 70% stuff.  The trick is to thoroughly saturate the cotton ball without filling it with so much alcohol that it is sopping wet.
Title: Re: Just say "no" to yeast rinsing
Post by: erockrph on July 16, 2014, 03:38:04 PM
What's your source for 95% ethanol?  Everclear?  Something lab-grade?

Everclear works well; however, its sale is banned in many states.

Quote
How do you know how long to wait?  I just guess, but I'm never sure.

I flame isopropyl off of glass, which is why I prefer to use borosilicate (Pyrex, Kimax) glassware for yeast storage.   I wait until the surface is visually dry on plastic. Ninety-one percent isopropyl flashes off quickly if applied lightly.  That's why I use it and not the garden variety 70% stuff.  The trick is to thoroughly saturate the cotton ball without filling it with so much alcohol that it is sopping wet.

While high concentration IPA or ethanol would definitely be preferred for applications where it is being flamed off, the 70% concentration is preferred for surface sterilization. While IPA and ethanol do have a short contact time for most pathogens, it isn't instant. The higher concentrations have the potential of flashing off before the necessary contact time has been achieved.

In addition, while there is no conclusive data that I have seen, the consensus seems to be that a minimum amount of water is needed for alcohol to be effective. The idea is that the water is required for protein denaturation. High concentration alcohol is extremely hygroscopic (i.e., it draws water out of solution, the air, etc.). The end result is that it could potentially dry out the cell membrane, preventing its ability to enter the cell. The quoted range of concentrations where alcohol is generally considered most effective is in the 60-80% range, and effectiveness falls off rapidly below 50%.

In healthcare applications, we use 70% ethanol or IPA almost exclusively for sterilizing surfaces. If I were to use a commercially available liquor in my home brewery, I would choose 151 proof rum over vodka (too low ethanol concentration) or Everclear (too high).
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on July 16, 2014, 03:42:26 PM
I went back and re listened to Brew strong episode on yeast rinsing because I started wondering why a guy who knows so much about it that he wrote the yeast book, would do rinsing... in the middle somewhere, JZ does mention that he racks the beer, tyen swirls the yeast into suspension in the remaining beer, flames the carboy opening, then transfers the yeast to a sanitary vessel. He stores it like that, on the beer. He then rinses prior to pitching.

I missed that part when I was rinsing. I would rinse on racking day and store in the rising water. In any even, I never noticed a marked improvement in my final product from rinsing so I quit doing it. I also limit my re pitching to about 3 generations.

On this subject im doing the denny method and calling it good enuff for me.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 16, 2014, 08:10:14 PM
I use 91% and 70% isopropyl alcohol.  I use 91% isopropyl alcohol when culturing because it burns much better than 70% isopropyl alcohol (I use borosilicate glassware almost exclusively).  I use 70% isopropyl alcohol to wipe down the table that I use when conducting aseptic transfers because it is much cheaper than 91% isopropyl alcohol.


I do not know if this study is dated, but it appears to be interesting research related to the subject. 

http://www.ncbi.nlm.nih.gov/pubmed/9801287


"Surgical hand disinfection with alcohols at various concentrations: parallel experiments using the new proposed European standards method.
Rotter ML1, Simpson RA, Koller W.
Author information
Abstract
OBJECTIVES:

To establish the concentration of isopropanol that exerts the same immediate and sustained effects as n-propanol 60% v/v in surgical scrubbing, and to assess the performance of the test method proposed as the European standard in parallel experiments.
DESIGN:

Isopropanol at concentrations of 70%, 80%, and 90% v/v was tested in comparison with n-propanol 60%, the proposed reference preparation, in the draft method proposed by the European standard. A Latin square design was used with four balanced blocks of five volunteers each in four experimental runs that were spaced by intervals of 1 week each. Volunteers were allotted randomly to one of the four blocks. Independently, the volunteers' right and left hands also were randomized into two groups for the assessment of either immediate or sustained effects.
SETTING:

Two laboratories supervised by two investigators, one from Vienna, Austria, and one from London, The United Kingdom.
METHOD:

The release of skin flora from the fingertips of clean hands was assessed before and after treatment by immediate sampling from one hand and by sampling of the other, gloved hand after 3 hours. The mean log10 reductions (RF) of bacterial release achieved by rubbing the alcoholic preparations for 3 minutes onto the hands were established.
RESULTS:

For both experiments, the immediate effects of isopropanol 70% (RF, 2.0 and 2.1, respectively) were significantly smaller than those of the reference n-propanol 60% (RF, 2.4 and 2.6, respectively). This also was found with the sustained effects (RF, 0.7 and 1.1 vs 1.0 and 1.6, respectively). At 90%, isopropanol equalled the immediate effect of n-propanol 60%, whereas at 80% it proved slightly (although not significantly) less active. There were no significant differences in the results of both investigators. The sustained effects of isopropanol 80% and 90% were both larger than the reference in Vienna but were found smaller by the London investigator; none of the differences were significant. Mean RFs were significantly different between Vienna and London with n-propanol 60% and isopropanol 70%, but not with isopropanol at 80% or 90%.
CONCLUSIONS:

At 90%, isopropanol is as effective as n-propanol 60%, which was proposed by the European Committee for Standardization as a reference in testing products for surgical hand disinfection. It could, therefore, serve as an alternative if the proposed agent is undesirable for any reason. In parallel experiments by two investigators, the proposed test method proved well workable; the results were very similar and the conclusions identical.
"

Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 16, 2014, 08:16:36 PM
He then rinses prior to pitching.

If a brewer is going to rinse, the time to do it is right before pitching, as the yeast culture does not spend a long period of time in a nutrient-free, high-pH solution.

By the way, I believe that Jamil only wrote the more applied parts of Yeast.

Quote
On this subject im doing the denny method and calling it good enuff for me.

It's the not the Denny method.  I use basically the same method (see paragraph number 4 of the original post in this thread), and so does every other experienced brewer that I now.
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on July 16, 2014, 08:33:44 PM
For several months I've been doing it that way. Now I know that Denny also does it that way. Hopefully when I refer to it as the Denny method, no one loses any royalties.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on July 16, 2014, 08:40:06 PM
The idea is that the water is required for protein denaturation. High concentration alcohol is extremely hygroscopic (i.e., it draws water out of solution, the air, etc.). The end result is that it could potentially dry out the cell membrane, preventing its ability to enter the cell. The quoted range of concentrations where alcohol is generally considered most effective is in the 60-80% range, and effectiveness falls off rapidly below 50%.

You brought up an important concept that we can tie to fermentation.  The reason why we oxygenate wort at the beginning of fermentation is that yeast cells use oxygen in the production of ergosterol and unsaturated fatty acids (UFA).  Ergosterol and UFAs make yeast cell membranes more pliable.  As yeast cells take in nutrients and expel waste through their cell membranes, a pliable cell membrane is critical to cell health.  It is also critical to alcohol tolerance.  Yeast cells stop fermenting beyond a certain percentage of alcohol because of what you mentioned; namely, the hygroscopic nature of ethanol.   Basically, yeast cells are unable to pass nutrients and waste through their cell membranes because they become dehydrated.
Title: Re: Just say "no" to yeast rinsing
Post by: tommymorris on July 16, 2014, 09:52:00 PM

For several months I've been doing it that way. Now I know that Denny also does it that way. Hopefully when I refer to it as the Denny method, no one loses any royalties.

Now I am confused. Where do I send my check?


Sent from my iPhone using Tapatalk
Title: Re: Just say "no" to yeast rinsing
Post by: erockrph on December 14, 2014, 06:40:05 PM
This thread has been referenced so often that we should consider making it a sticky.
Title: Re: Just say "no" to yeast rinsing
Post by: bboy9000 on December 15, 2014, 04:23:55 AM

Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.


One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol

So just spraying the surfaces with Star San isn't good enough? 
Title: Re: Just say "no" to yeast rinsing
Post by: morticaixavier on December 15, 2014, 03:56:51 PM

Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.


One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol

So just spraying the surfaces with Star San isn't good enough?

not for yeast ranching. If you're just repitching once or twice it's not a big deal but if you are going to be culturing from a couple million cells it becomes more important to get as close to sterile as possible and star san doesn't do that.
Title: Re: Just say "no" to yeast rinsing
Post by: erockrph on December 15, 2014, 04:09:41 PM

Can you define your entire process for us S?  Ill try it, the only reason i was rinsing is because it was the most used method i could find instructions for.


One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol

So just spraying the surfaces with Star San isn't good enough?

not for yeast ranching. If you're just repitching once or twice it's not a big deal but if you are going to be culturing from a couple million cells it becomes more important to get as close to sterile as possible and star san doesn't do that.
+1 - It mainly depends on your definition of "good enough". If you're going to be pitching right into another batch in a day or two, then it's probably good enough. But any miniscule contamination will increase over time. When you're talking about long-term storage or smaller culture sizes, then contamination can take over much more easily. Alcohol will sterilize, while Star-San will not guarantee sterility.
Title: Re: Just say "no" to yeast rinsing
Post by: Jimmy K on December 15, 2014, 05:07:12 PM

One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol
I'm a biologist, but not a microbiologist. I heard several years ago that 70% ethanol sterilizes better than 95% ethanol because the water helps denature cell proteins. I don't remember where I heard this, so any idea if it's true?
Title: Re: Just say "no" to yeast rinsing
Post by: HoosierBrew on December 15, 2014, 05:14:28 PM

One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol
I'm a biologist, but not a microbiologist. I heard several years ago that 70% ethanol sterilizes better than 95% ethanol because the water helps denature cell proteins. I don't remember where I heard this, so any idea if it's true?

I read the same from a few sources several years back (don't remember the source).  I remember references to the 70% causing more disruption to the cell walls. Maybe it does that by interaction with the proteins (?).
Title: Re: Just say "no" to yeast rinsing
Post by: erockrph on December 15, 2014, 06:02:54 PM

One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol
I'm a biologist, but not a microbiologist. I heard several years ago that 70% ethanol sterilizes better than 95% ethanol because the water helps denature cell proteins. I don't remember where I heard this, so any idea if it's true?

That's the theory. The idea is that 95% ethanol is so hygroscopic that it could potentially dehydrate the cell membrane before the ethanol can pass into the cell. I've never seen any experimental data proving this, however. Still, if I were to start yeast ranching in earnest, I would probably use 70% ethanol, or maybe 151-proof rum as my sterilization agent.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on December 15, 2014, 06:51:47 PM
I use 70% to wipe down my work surface.  I use 91% isopropyl or 95% grain alcohol for wiping any surface that will be flamed.  I also keep my loop immersed in 91% isopropyl or 95% grain alcohol between inoculations while subculturing or plating (I use a culture tube filled with alcohol).   I usually start a culturing session by flaming the loop until it is red hot.  From that point forward, I merely pull the loop out of the culture tube that is filled with alcohol, ignite the alcohol, and then perform the transfer as soon as the alcohol burns off.  The process results in sterile loop that requires much less time to cool to a temperature where it no longer fries the cells on contact.
Title: Re: Just say "no" to yeast rinsing
Post by: bboy9000 on December 15, 2014, 10:13:17 PM
So the mason jar of Pacman stored under a beer layer that's been in my fridge for 4 months may not be good?  That stuff is hard to get here in Missouri now that BrewCraft has opened the east coast warehouse.  They don't carry Pacman but that's the warehouse that ships to KC.
Title: Re: Just say "no" to yeast rinsing
Post by: morticaixavier on December 15, 2014, 10:58:01 PM
So the mason jar of Pacman stored under a beer layer that's been in my fridge for 4 months may not be good?  That stuff is hard to get here in Missouri now that BrewCraft has opened the east coast warehouse.  They don't carry Pacman but that's the warehouse that ships to KC.

it's probably fine. there are so many cells (10's or 100's of billions) that have been kept carefully in their own specially engineered environment designed to preclude other organisms as much as possible.

That being said, are you willing to risk a batch? I would be, S.Cerv might not be.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on December 16, 2014, 01:10:18 AM
That being said, are you willing to risk a batch? I would be, S.Cerv might not be.

You're talking about a guy who spends a C-note on yeast strains that have almost no brewing data.  I could be ordering and pitching a brewery contaminant for all I know.  ;D 

With that said, I have pitched six month-old crops without making a starter;  however, it's not something that I would recommend.   I usually wake a four-month old crop up before pitching it.  That way, the viable cells can be separated from the dead cells.

Title: Re: Just say "no" to yeast rinsing
Post by: YooperBrew on December 16, 2014, 02:11:09 AM
That being said, are you willing to risk a batch? I would be, S.Cerv might not be.

You're talking about a guy who spends a C-note on yeast strains that have almost no brewing data.  I could be ordering and pitching a brewery contaminant for all I know.  ;D 

With that said, I have pitched six month-old crops without making a starter;  however, it's not something that I would recommend.   I usually wake a four-month old crop up before pitching it.  That way, the viable cells can be separated from the dead cells.

I'm definitely no microbiologist, but many of my jars get the "sniff test" when I pull them out of the fridge.  First, they should look ok- no black spots, weird things, etc.  And when you open it, it should smell like a yeasty beer smell.  If there is any weird odor- sour, fecal, etc, but plain old "not right"- the jar should be discarded. 

I try to use my jars relatively quickly, but sometimes they sit too long and I don't have any pangs about tossing them if they aren't right.  It's not scientific at all, but as a long time brewer sometimes just a "not right" feeling is as good as a microscope.   Other times, well, no.  But the sniff test will definitely tell you if it's "off" without a microscope, as there is no mistaking severe problems (like 'fecal').
Title: Re: Just say "no" to yeast rinsing
Post by: 69franx on December 16, 2014, 02:37:59 AM
I think you're right, I would recognize fecal... And not pitch
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on December 16, 2014, 10:28:01 AM
I think you're right, I would recognize fecal... And not pitch
Most styles call for low to no shart aroma or flavor. Just sayin
Title: Re: Just say "no" to yeast rinsing
Post by: HoosierBrew on December 16, 2014, 01:10:36 PM
I think you're right, I would recognize fecal... And not pitch
Most styles call for low to no shart aroma or flavor. Just sayin

Funny stuff.   AB's new slogan :  "Our beer's not sharty  -  we promise."
Title: Re: Just say "no" to yeast rinsing
Post by: Jimmy K on December 16, 2014, 03:15:23 PM
I think you're right, I would recognize fecal... And not pitch
Most styles call for low to no shart aroma or flavor. Just sayin

Funny stuff.   AB's new slogan :  "Our beer's not sharty  -  we promise."
Miller Lite: Great taste, less shart
 
This bring new meaning to Heineken refreshes the parts other beers cannot reach.
Title: Re: Just say "no" to yeast rinsing
Post by: HoosierBrew on December 16, 2014, 03:24:47 PM
I think you're right, I would recognize fecal... And not pitch
Most styles call for low to no shart aroma or flavor. Just sayin

Funny stuff.   AB's new slogan :  "Our beer's not sharty  -  we promise."
Miller Lite: Great taste, less shart
 
This bring new meaning to Heineken refreshes the parts other beers cannot reach.

Coors :  Made from shart-free Rocky Mountain water.    :)
Title: Re: Just say "no" to yeast rinsing
Post by: Wort-H.O.G. on December 16, 2014, 03:29:52 PM
I think you're right, I would recognize fecal... And not pitch
Most styles call for low to no shart aroma or flavor. Just sayin

Funny stuff.   AB's new slogan :  "Our beer's not sharty  -  we promise."
Miller Lite: Great taste, less shart
 
This bring new meaning to Heineken refreshes the parts other beers cannot reach.

Coors :  Made from shart-free Rocky Mountain water.    :)

Molson Canadian: It Sharts Here
 Guinness: out of the Shartness comes the light
Title: Re: Just say "no" to yeast rinsing
Post by: denny on December 16, 2014, 04:28:37 PM
So the mason jar of Pacman stored under a beer layer that's been in my fridge for 4 months may not be good? 

Or it may be fine.  Make a starter and find out.
Title: Re: Just say "no" to yeast rinsing
Post by: The Professor on December 16, 2014, 04:34:29 PM
So the mason jar of Pacman stored under a beer layer that's been in my fridge for 4 months may not be good? 

Or it may be fine.  Make a starter and find out.

Right.
As a very wise philosopher once said:  "You'll never know until you check it out..."
Title: Re: Just say "no" to yeast rinsing
Post by: rbowers on December 16, 2014, 07:35:17 PM
I was referred to this thread not too long ago when I asked a question about yeast rinsing and so I tried the new method of swirling the yeast with a little of the left over beer then decanting off once settled.  It really worked great- it seems the washing process at best is just an extra unnecessary step and at worse may lead to other problems.  I went ahead and made some fresh wort to feed it and it's bubbling away in a flask ready to go for brew day in a week or two.  Thanks for the good advice!
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on December 17, 2014, 09:59:51 AM
I was referred to this thread not too long ago when I asked a question about yeast rinsing and so I tried the new method of swirling the yeast with a little of the left over beer then decanting off once settled.  It really worked great- it seems the washing process at best is just an extra unnecessary step and at worse may lead to other problems.  I went ahead and made some fresh wort to feed it and it's bubbling away in a flask ready to go for brew day in a week or two.  Thanks for the good advice!
Awesome stuff huh?

Not picking on you, but its not a new method. If you think about it its the oldest method. Yeast have been storing themselves in whatever they have fermented since they first became yeast...
Title: Re: Just say "no" to yeast rinsing
Post by: jzamora3 on January 14, 2015, 02:17:03 AM
So I just bottled my milk stout and didn't rinse. Now I have this and I'm not too sure what layers I should transfer to my mason jars. Can you help me figure it out? Thanks!!
(http://cdn.homebrewtalk.com/attachments/f163/248687d1421200371-harvesting-yeast-20150113_184608.jpg)
Title: Re: Just say "no" to yeast rinsing
Post by: jzamora3 on January 14, 2015, 02:19:16 AM
Don't know if it'd make a difference but the yeast used was Dannys favorite by wyeast
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on January 14, 2015, 01:44:42 PM
Personally, id dump it and start over. If I had to reuse it I would take a 100ml and build a starter.
Title: Re: Just say "no" to yeast rinsing
Post by: denny on January 14, 2015, 04:56:58 PM
Don't know if it'd make a difference but the yeast used was Dannys favorite by wyeast

Um...that's "Denny"....
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on January 14, 2015, 05:46:12 PM
So I just bottled my milk stout and didn't rinse. Now I have this and I'm not too sure what layers I should transfer to my mason jars. Can you help me figure it out? Thanks!!
(http://cdn.homebrewtalk.com/attachments/f163/248687d1421200371-harvesting-yeast-20150113_184608.jpg)

I can tell you where you went wrong. Your liquid to solid ratio is too low (it should be at least 1:1), which is why you did not achieve good separation.  You left too little liquid in your fermentation vessel when you racked, resulting in a fairly thick slurry after swirling.  The process works best when one leaves at least 1/4th of gallon of clear liquid behind with the break and yeast when racking.   I would swirl the solids into solution, wait a few minutes for the heaviest particulate matter to settle, and carefully decant the thinnest fraction.  The goal is not to attempt to obtain a squeaky clean crop, but more of a "clean enough" crop.  I would also not attempt to "bank" slurry. There are better ways to bank yeast.  Slurry should be approached as a short term way to hold yeast for one's next batch.

Title: Re: Just say "no" to yeast rinsing
Post by: Jimmy K on January 22, 2015, 01:43:23 PM
Don't know if it'd make a difference but the yeast used was Dannys favorite by wyeast

Um...that's "Denny"....
A wise man once said we should figure things out for ourselves.
Title: Re: Just say "no" to yeast rinsing
Post by: Joe Sr. on January 22, 2015, 04:36:37 PM
One habit that all brewers should get into is the habit of wiping all pouring surfaces with a cotton ball soaked with 95% ethanol (or 91% isopropyl alcohol if one is patient enough to allow it to flash off) before decanting any yeast culture (that includes starters and all steps in the starter process).  The pouring surface of a container holding a yeast culture should always be treated like it is contaminated.  Just as a nurse or doctor disinfects one's skin before injecting one with a syringe to ensure that the needle does not drag surface bacteria into the injection site, wiping the pouring surface of a container that contains a yeast culture  prevents the yeast culture from dragging any wild microflora that may be resting on the pouring surface into fresh media or wort.  It's a cheap insurance policy.

I work on the assumption that if the beer I'm cropping from isn't infected, then the sanitation is good and I don't need to bother wiping down the rim of my bucket before I pour.  Hasn't failed in hundreds of times.

Wow.  This thread just keeps going and going.

I do what Denny does, except I don't use buckets.  I use better bottles with the orange caps on them.  The bottle and cap are sanitized before the beer goes in and I assume they stay that way.  I haven't had any contamination issues from pouring directly into a sanitized container.  Been doing this for years.

I sometimes think we over-think things.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on January 23, 2015, 04:02:49 AM
Wow.  This thread just keeps going and going.

I do what Denny does, except I don't use buckets.  I use better bottles with the orange caps on them.  The bottle and cap are sanitized before the beer goes in and I assume they stay that way.  I haven't had any contamination issues from pouring directly into a sanitized container.  Been doing this for years.

I sometimes think we over-think things.

Wiping the pouring surface with an alcohol saturated cotton ball, cotton swab, or piece of cotton gauze is just a good habit to get into when transferring yeast.  I wipe and flame when transferring from a glass container.  It's a carry over from aseptic transfer technique.  The mouths of the culture tubes in which I prepare my slants have never been exposed to airbone dust since they and the solid media that they hold were sterilized with 250F moist heat at 15 PSI above sea level for 15 minutes, but the standard practice is to flame the mouth after removing the cap and before inoculating the slant.  It's an insurance policy against contamination.

Title: Re: Just say "no" to yeast rinsing
Post by: Joe Sr. on January 23, 2015, 04:22:19 AM
No doubt. I see no negatives to wiping with alcohol. I'd like to say I'll do it but since I haven't had any issues  I'm  just as likely to slack.
Title: Re: Just say "no" to yeast rinsing
Post by: JT on January 23, 2015, 11:06:21 AM
Wow.  This thread just keeps going and going.

I do what Denny does, except I don't use buckets.  I use better bottles with the orange caps on them.  The bottle and cap are sanitized before the beer goes in and I assume they stay that way.  I haven't had any contamination issues from pouring directly into a sanitized container.  Been doing this for years.

I sometimes think we over-think things.

Wiping the pouring surface with an alcohol saturated cotton ball, cotton swab, or piece of cotton gauze is just a good habit to get into when transferring yeast.  I wipe and flame when transferring from a glass container.  It's a carry over from aseptic transfer technique.  The mouths of the culture tubes in which I prepare my slants have never been exposed to airbone dust since they and the solid media that they hold were sterilized with 250F moist heat at 15 PSI above sea level for 15 minutes, but the standard practice is to flame the mouth after removing the cap and before inoculating the slant.  It's an insurance policy against contamination.
I could probably bump my game up a bit here.  Everything I use currently has been washed and sanitized, or in the case of the flask holding the yeast, covered with foil during propagation.  If I'm using a funnel to transfer into a carboy, you would wash, sanitize,  wipe with alcohol, then flame? Any OTC rubbing alcohol suffice or is there a percent I should be looking for?
Title: Re: Just say "no" to yeast rinsing
Post by: reverseapachemaster on January 23, 2015, 03:31:15 PM
Don't know if it'd make a difference but the yeast used was Dannys favorite by wyeast

Um...that's "Denny"....

Don't be such a stickler Danny.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on January 24, 2015, 02:18:09 AM
I could probably bump my game up a bit here.  Everything I use currently has been washed and sanitized, or in the case of the flask holding the yeast, covered with foil during propagation.  If I'm using a funnel to transfer into a carboy, you would wash, sanitize,  wipe with alcohol, then flame? Any OTC rubbing alcohol suffice or is there a percent I should be looking for?

With aseptic transfer, one not only flames the source and destination culture tubes, one also performs the transfer over a flame because it prevents airbone microflora from contaminating the culture (hot air rises). We are talking about transferring very tiny amounts of yeast that will be propagated into larger amounts of yeast at a later time.

With a normal yeast transfer, all we are attempting to do is to reduce the chance of picking up unwarranted native microflora during the transfer.   Hence, we only need to ensure that the lip of the container over which the culture will be poured has been cleaned of wild microflora before pouring.  Most wild microflora do not travel on their own.  They usually hitch a ride on house dust.  Even if you cannot see it, almost everything in one's house is covered with dust particles.  The lip of a carboy, flask, or any other container in which a rubber stopper has been inserted during propagation, fermentation, or cold storage will usually harbor some dust and wild microflora.  Wiping with an alcohol saturated cotton ball, cotton swab, or a piece of cotton gauze before pouring the yeast culture will reduce, if not completely remove that source of contamination. 

The process makes sense if one thinks about what a nurse or doctor does before he/she gives you an injection.  The alcohol prep is to prevent the needle from dragging microbes on your skin into the injection site.  In the case of a culture, wiping the pouring surface will help to prevent the yeast culture from dragging any microbial contamination that may have been resting on the pouring lip into one's fermentation vessel.  A small amount of bacteria can overtake a much larger amount of yeast because the bacteria cell population increases 8-fold every time the yeast cell population doubles.  If we were to normalize the propagation period between yeast and bacteria (bacteria multiplies three times faster than yeast), the growth equations would be:

yeast_cell_count = initial_cell_count * 2n, where n = elapsed time in minutes since the end of the lag phase / 90

bacteria_cell_count = initial_cell_count * 8n, where n = elapsed time in minutes since the end of the lag phase / 90


If we run the numbers, it should become crystal clear why one wants to pitch a large, healthy yeast culture while doing everything possible to minimize the opportunity for bacteria to catch a ride into one's yeast crop, starter, or fermentation vessel.  It should also become clear why the growth phase is called the exponential phase.


Cell counts at 90 minutes

yeast_cell_count = initial_yeast_cell_count * 21 =  initial_cell_count * 2
bacteria_cell_count = initial_bacteria_cell_count * 81 = initial_cell_count * 8


Cell counts at 180 minutes

yeast_cell_count = initial_yeast_cell_count * 22 =  initial_cell_count * 4
bacteria_cell_count = initial_bacteria_cell_count * 82 = initial_cell_count * 64


Cell counts at 270 minutes

yeast_cell_count = initial_yeast_cell_count * 23 =  initial_cell_count * 8
bacteria_cell_count = initial_bacteria_cell_count * 83 = initial_cell_count * 512


Cell counts at 360 minutes

yeast_cell_count = initial_yeast_cell_count * 24 =  initial_cell_count * 16
bacteria_cell_count = initial_bacteria_cell_count * 84 = initial_cell_count * 4096


Cell counts at 450 minutes

yeast_cell_count = initial_yeast_cell_count * 25 =  initial_cell_count * 32
bacteria_cell_count = initial_bacteria_cell_count * 85 = initial_cell_count * 32768


Cell counts at 540 minutes

yeast_cell_count = initial_yeast_cell_count * 26 =  initial_cell_count * 64
bacteria_cell_count = initial_bacteria_cell_count * 86 = initial_cell_count * 262,144


Cell counts at 630 minutes

yeast_cell_count = initial_yeast_cell_count * 27 =  initial_cell_count * 128
bacteria_cell_count = initial_bacteria_cell_count * 87 = initial_cell_count * 2,097,152


Cell counts at 720 minutes

yeast_cell_count = initial_yeast_cell_count * 28 =  initial_cell_count * 256
bacteria_cell_count = initial_bacteria_cell_count * 88 = initial_cell_count * 16,777,216

Pitching a large culture limits the number of replication periods that are necessary to reach maximum cell density in a fermentation.  Reducing the number of yeast replication periods, reduces the number of replication periods for bacteria that can withstand a yeast culture's other defenses.  The bacteria population increases every time we repitch a bottom-cropped culture because each repitch is an opportunity for the existing bacterial load to increase.  One of the reasons why top-cropping is preferred over bottom cropping when repitching is because it naturally purifies the culture.  Top cropping does so because bacteria and wild yeast generally do not floc to the top.  This phenomenon is the basis of Max Emil Julius Delbrück's "Natural Pure Culture" method.  Max was a German agricultural chemist who duked it out with Emil Christian Hansen  for the hearts and minds of brewers at the beginning the industrial brewing era.  The name Emil Christian Hansen should be one that all brewers recognize, as Emil was the first brewing scientist to isolate a pure yeast culture.  That culture is known as Carlsberg Bottom Yeast No. 1.  It's still available today from culture collections.  The CBS-KNAW number is CBS 1513.  The National Collection of Yeast Culture number is NCYC 396.  I am fairly certain that Miller's strain is descended from Carlsberg Bottom Yeast No. 1.  The founder of Carlsberg, Jacob Christian Jacobsen, was generous with Emil's discovery.
Title: Re: Just say "no" to yeast rinsing
Post by: phunhog on January 25, 2015, 09:05:19 PM
What about using chlorine dioxide tablets to kill/greatly reduce the numbers of bacteria in your yeast starter? I do this anytime I am stepping up an older starter to a pitchable quantity.  I agree that prevention is the best but......most of us are playing with yeast in less than perfect conditions.  Seems like cheap insurance.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on January 25, 2015, 09:33:30 PM
Like acid washing, chlorine dioxide treatment is a short term fix to a long term problem.  Sooner or later, one is going to have to acquire a new culture or grow a new culture from slant.

Title: Re: Just say "no" to yeast rinsing
Post by: ridesalot on January 30, 2015, 06:02:05 AM
one thing I really like about reusing yeast, if you are making 3-4 batches of beer that can use same style of yeast, by the 4th pitch your amount of yeast is gigantic. on my 4th batch I really didn't make a starter, per se, I just wanted to wake the buggers up. in a 2litre flask I had almost one liter of solid yeast. big pitch, activity in only 2 hours. great beer, im drinking it now.  it was white labs 13 london ale yeast. 
Title: Re: Just say "no" to yeast rinsing
Post by: morticaixavier on January 30, 2015, 03:23:07 PM
one thing I really like about reusing yeast, if you are making 3-4 batches of beer that can use same style of yeast, by the 4th pitch your amount of yeast is gigantic. on my 4th batch I really didn't make a starter, per se, I just wanted to wake the buggers up. in a 2litre flask I had almost one liter of solid yeast. big pitch, activity in only 2 hours. great beer, im drinking it now.  it was white labs 13 london ale yeast.

what was the gravity? that's an s-load of yeast. even for a big 1.100+ beer I only use about 12-16 ounces of fairly thin slurry.
Title: Re: Just say "no" to yeast rinsing
Post by: dilluh98 on May 03, 2015, 06:23:23 PM
Not to sidetrack the thread but if I were to use the bottom cropping methods outlined by S. cerevisiae on the first page (paragraph 4, I believe) would the "thin slurry," i.e., 1 billion/mL setting on something like Mrmalty.com give me a decent estimate in terms of starter requirements (if not pitching immediately)?

I've heard that most of the calculators out there give slightly (if not grossly) over-shot number in terms of what needs to be pitched and that the numbers get a bit fuzzy anyway due to a lot of factors that can't be accounted for by a few inputs on an online calculator. In that vein, can there be a point at which you've pitched too much yeast? Ridesalot above stated pitching a full liter of solid yeast - good lord!
Title: Re: Just say "no" to yeast rinsing
Post by: musseldoc on May 04, 2015, 01:10:10 PM
I see my slurries go darker, faster when I leave them in beer.  I see nice creamy-white slurries longer when stored in autoclaved water.  I just started a new pitch of WLP004 from a slurry I saved from Nov 2014.  Still creamy-white.  About a day lag, but turned a 4L flask white (10 ml of slurry pitched) in 48 hrs. Some of these have been rinsed once, some are just crashed and I haven't got to them.  Point is the small bottle with WLP004 from 11/14. 

(https://lh4.googleusercontent.com/-_bv6tbfrQd8/VUdukzzxMzI/AAAAAAAAACk/9W6ch6_bYtI/w640-h480-no/IMG_3481.JPG)

Any residual sugars, dextrins, albumins, etc. will be nutrition for any contamination.  Any breakdown of dead yeast will serve as nutrient for them as well.  Pure distilled water ends up around 5.2-5.3 pH, so it is slightly acid anyways, simulating the antibacterial properties of beer pH.  I believe that removing any fouling compounds from your slurry can only improve viability and storage life.  If you are repitching quickly, then it is a moot point really.  If you are putting a small sample of your yeast starter back as an inoculum for a future starter, then you should consider sterile distilled water as the storage medium.  Even the yeast suppliers are championing it for long term storage.  Didn't Hansen also show viability of 14 years when stored in de-oxygenated distilled water?

http://www.probrewer.com/library/archives/keeping-your-yeast-healthy-longer/

http://www.danstaryeast.com/articles/viability-storage-and-measurement

http://hbd.org/brewery/library/SterileDW1096.html
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on May 04, 2015, 10:00:54 PM
It's not about the color of a crop.  The color of the yeast darkens because the green beer darkens over time and stains the cells.  Sure, some of the color change is due to aging, but most of the change is due to staining.  The only way to know the viability of a yeast culture is to stain it under a microscope.  If you are obtaining a lot of organic matter with your crop, then you need to revisit your casting-out and cropping techniques.

Growing a starter from a crop taken on 11/14 is not a major feat.  Five to five and half months is not a long time in the grand scheme of things when one considers the number of cells in a crop, even a small crop.  I do not recommend it, but I have pitched crops that were that were much older without making a starter. 

I am not the only one who has stated that yeast should not be stored outside of beer. Fermentis' parent  company, Lesaffre, has an army of Ph.D. microbiologists, biochemists, and biochemical engineers on staff.   They are a huge multinational company that handles yeast strains used in a wide variety of applications, including of human research.

Here's what they have to say:

www.fermentis.com/wp-content/uploads/2010/07/2010_TT_EN_HD.pdf

"In case of repitching, yeast must not be stored out of beer for long periods, even at low temperatures, as yeast glycogen levels will fall causing slow fermentations."

Additionally, a pH of 5.2 is not low enough to prevent bacteria from growing.  The pH has to be taken down to below 4.6 to halt most bacteria, especially pathogens like Clostridium botulinum.    The reason why pathogens do not grow in beer is because the pH is below 4.6.

If you consider residual sugars, dextrins, albumins to be major sources of food for wild microflora (most of which will never start because the pH is too low), then you more than likely have never prepared any laboratory yeast propagation media.  Have you ever heard of YPD or MYGP?  Guess what the "Y" stands for in these media?  It stands for Yeast extract, which is the contents of yeast cells (the other part is known as "yeast hulls" after the extraction process has been completed). 

We know that rinsing yeast with and storing it under water removes the protective force field that the culture built for itself.  Well, it also accelerates glycogen depletion.  Guess what happens when yeast cells exhaust their glycogen reserves?  They lyse and release their contents into the medium. Yeast extract is far more nutritious to wild microflora than what is left over after fermentation. 

http://en.wikipedia.org/wiki/Yeast_extract

"Yeast extract is the common name for various forms of processed yeast products made by extracting the cell contents (removing the cell walls); they are used as food additives or flavourings, or as nutrients for bacterial culture media. They are often used to create savoury flavours and umami taste sensations, and can be found in a large variety of packaged food including frozen meals, crackers, snack foods, gravy, stock and more. Yeast extracts in liquid form can be dried to a light paste or a dry powder."

Finally, the whole rinsing and storing yeast under water thing is misinterpretation of research performed by the ATCC over twenty years ago.  That research was conducted to find a means by which to store yeast for long periods of time without the need for refrigeration in countries such as Africa.  However, that technique requires all traces of organic material and nutrients to be removed via centrifudge.  The culture that will be stored also has to be propagated under aseptic conditions using absolutely sterile media to avoid the threat of contamination. Finally, the stored yeast has be restarted under laboratory conditions, which makes the method impractical in a home brewing environment.  It is much easier for small-scale brewers that lack access to -196C cryostorage to store yeast on subcultured slants.   I have maintained yeast cultures on slant since 1993.

Here are a few old photos of my current bank:

(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/MyCurrentBank1_zps31b27281.jpg)

(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/CCyeast1_zpsdc754fa7.jpg)

(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/CulturesIIsolated1_zps0e5d67cf.jpg)


The conclusion that all amateur brewers who are serious about maintaining a yeast bank reach is that liquid cultures are not the answer.  It's much easier to verify condition and purity when yeast is stored on slant.
Title: Re: Just say "no" to yeast rinsing
Post by: brulosopher on May 04, 2015, 10:11:25 PM
Little late to the party, but I like your style! I've been overbuilding and harvesting from starters for years, but after a recent xBmt, I'm starting to think I might just start saving 500 mL of the spent cake for use on later batches.
Title: Re: Just say "no" to yeast rinsing
Post by: musseldoc on May 05, 2015, 01:23:44 AM
Wow, that's a lot of personal attacks over someone posting something contrary to your opinion. 
Title: Re: Just say "no" to yeast rinsing
Post by: Stevie on May 05, 2015, 03:11:13 AM

Wow, that's a lot of personal attacks over someone posting something contrary to your opinion.
I'll be the first to admit to getting into arguments with Mark, but I don't see his response as an attack.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on May 05, 2015, 08:26:14 AM
I'll be the first to admit to getting into arguments with Mark, but I don't see his response as an attack.

My post was not meant as a personal attack.  I may have made an assumption or two, which as we all know can result in making an a** out you and me. :(  However, I was merely attempting to make a point.

One thing that is critical about the storage of yeast under autoclaved distilled water is that all traces of nutrients have to be removed from the culture in order to force dormancy; otherwise, the culture will just burn through its glycogen reserves at a faster pace than it would if it had been stored under beer.   This requirement was made clear when the ATCC was offering courses on the technique in Rockville, Maryland back in the nineties (Rockville is a Washington, D.C. suburb).  I live in Maryland.  I attended that course.  The technique was developed for third-world countries.  It involves storing well isolated colonies in autoclaved distilled water.  As colonies grow on the surface of solid media, one can harvest nutrient free yeast cells. 

If one reads the links provided by mussledoc, both Clayton Cone and Chris White acknowledge this requirement.  A lot of home brewers want to gloss over it in an attempt to generalize the technique to include rinsed crops (yeast rinsing is a darling on one the large home brewing forums).  However, I have found no published data that supports the long-term storage of rinsed cropped yeast under absolutely sterile water.

Clayton Cone's response to the question about storage of yeast under water:

"Ad 3) It depends on how you store your yeast. There are reports that you can store yeast up to 1 year in distilled water if all sugars are removed. We have a little program running to test this and after one month the yeast is still fermenting well. But it is critical that all sugars are removed. A lot of breweries keep their yeast for up to a month under water (removing the wort/sugar residuals) without any problems."


From the Chris White article:

"Storing yeast under water, as opposed to under beer, is becoming more popular. Sterile distilled water storage puts yeast in a resting state, and some reports suggest yeast can be stored in this manner for years, with no refrigeration. Storage under water is generally done with small quantities of yeast, which are then propagated in a lab. But it is possible that this can be applied to storage of yeast slurries. Some brewers are now trying this. The key is to use sterile distilled water and wash the yeast slurry several times in the sterile distilled water to remove any traces of beer. This is best done with a centrifuge, but that is impractical for most craft brewers. White Labs has had mixed success with sterile water storage, so time will tell if this procedure will work for craft breweries. "

A key takeaway here is that Chris acknowledged that White Labs has experienced mixed success with the technique.  White Labs has a fully-equipped quality control lab at their disposal. 


Title: Re: Just say "no" to yeast rinsing
Post by: ynotbrusum on May 05, 2015, 12:07:19 PM
Wow, that's a lot of personal attacks over someone posting something contrary to your opinion.

Please don't take the response as a personal attack.  All views are welcome here, but Mark started the thread to assert why yeast rinsing at the homebrew level is not the preferred route, typically.  Since slurry use by direct repitch is so widespread, many of us here follow that approach.  Through purely anecdotal evidence, admittedly, following the Denny Conn approach of trying it for yourself and seeing what works best, I simply time my beers to have viable repitch yeast handy from one batch to the next and it has worked great.  The greatest number of clean, non-mutated re-pitches for me was in excess of 20.  By then, I figured I had stretched my luck and went to a new lab pitch from White Labs.  I have stored several months and re-propagated without problems, but frankly I get my money's worth out of a batch if I use it 4-5 times.  Also, I rarely make starters any more, opting for small batches that I step up until I get to my desired and typical batch (10 gallons for me).

One thing is for sure - YMMV, so try different things and see what works best for you.


Oh and one further thing to note: Mark uses amateur as a distinction from professional Brewers who brew for a living and likely have lab support to some degree.  He is not using it in any pejorative  sense.
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on May 05, 2015, 12:43:52 PM
I chuckle at myself when I think back over the past couple years. My brewing knowledge journey started with the Palmer free on line book. By the way I don't think it will ever end. So I know that what I know now might not be entirely correct. My yeast use started with sprinkling US05, then rehydrating, then pitching smack packs, then making shook starters, the stir plate starters, the repitching x amount of slurry, the rinsing, then back to not rinsing, then to making stir plate starters with 100ml of slurry, to now I usually just make a oxygenated nonstirplate starter with a fresh smack pack.

Last year I started making sours in the summer. Doubling my sour production this summer. So I've been listening to the sour hour, reading Chad Yackobson's brett dissertation page, and any other brett lacto pedio info I can find. This go around is a little easier on me because ive learned not to take everything as fact the first time I read it. When I share info I try to delineate between what ive heard and what I've experienced. Keeping always in mind that I am the furthest thing from an expert or scientist.

I really dig mark's posts on yeast. Much of it is deep water for me. But I think he's right on regarding yeast rinsing and storing on water. Assuming perfect sanitation, the best you can hope for with rinsing and storing with water is that you might remove some trub, you might remove the most nonfloculant yeast (probably the liveliest or most attenuating of the bunch), and leave the survivors in a nutrient depleted solution. Not to mention that beer should be about 4.5 ph or lower, while water is usually 6.5 or higher. Anything over 4.5 runs the risk of incubating contamination, or so I've heard.

Not to mention that none of my yeast handling techniques ive tried along the way ever obviously improved the quality of my beer, except for using a fresh smack pack in an oxygenated nonstir starter, with autoclaved dme starter wort that had nutrient included. That method has given me the most reliability. Im also a new fan of gel fining the primary, so I'm fine with shelling out $7 for a new pitch. So is my LHBS ;-)
Title: Re: Just say "no" to yeast rinsing
Post by: Phil_M on May 05, 2015, 01:03:11 PM
Jim, are you using a pressure cooker as an autoclave?
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on May 05, 2015, 02:12:05 PM
Not to mention that none of my yeast handling techniques ive tried along the way ever obviously improved the quality of my beer, except for using a fresh smack pack in an oxygenated nonstir starter, with autoclaved dme starter wort that had nutrient included. That method has given me the most reliability. Im also a new fan of gel fining the primary, so I'm fine with shelling out $7 for a new pitch. So is my LHBS ;-)

Maribeth Raines and Jeff Mellem used to sell a product called SuperWort.  I would love to know what was in that mixture. 
Title: Re: Just say "no" to yeast rinsing
Post by: erockrph on May 05, 2015, 02:19:08 PM
Not to mention that none of my yeast handling techniques ive tried along the way ever obviously improved the quality of my beer, except for using a fresh smack pack in an oxygenated nonstir starter, with autoclaved dme starter wort that had nutrient included. That method has given me the most reliability. Im also a new fan of gel fining the primary, so I'm fine with shelling out $7 for a new pitch. So is my LHBS ;-)

Maribeth Raines and Jeff Mellem used to sell a product called SuperWort.  I would love to know what was in that mixture.
Happy Cinco de Mayo everybody!  ;D
(http://www.delicioussparklingtemperancedrinks.net/Images/MaltaGoya.jpg)
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on May 05, 2015, 05:59:59 PM
I do 1.035ish wort with extra light DME and about a half teaspoon of wyeast nutrients. Seems to do the job nicely. Tho it would be interesting to try a maltose glucose peptone servomycyes combo.
Title: Re: Just say "no" to yeast rinsing
Post by: ynotbrusum on May 05, 2015, 06:19:03 PM
Not to sidetrack the thread but if I were to use the bottom cropping methods outlined by S. cerevisiae on the first page (paragraph 4, I believe) would the "thin slurry," i.e., 1 billion/mL setting on something like Mrmalty.com give me a decent estimate in terms of starter requirements (if not pitching immediately)?

I've heard that most of the calculators out there give slightly (if not grossly) over-shot number in terms of what needs to be pitched and that the numbers get a bit fuzzy anyway due to a lot of factors that can't be accounted for by a few inputs on an online calculator. In that vein, can there be a point at which you've pitched too much yeast? Ridesalot above stated pitching a full liter of solid yeast - good lord!

We almost lost your inquiry in the rush to discuss other stuff above.  I'm no scientist, nor have I played one on TV, but I would use a relatively thin slurry setting on Mr. malty, doing what Mark describes (a quart or so of beer left to swirl up the slurry).  Too much yeast? Yes, it seemed to create a bit of a flabby beer - not all of the qualities that come from a pitch that allows the yeast to go through its full cycle - kind of stressing it by not allowing as much reproduction as would be the case with a lesser, but adequate pitch.  I had that result with a very large pitch in a pretty modest lager wort.  You could drink it, but it was pretty much lifeless.
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on May 08, 2015, 12:33:11 AM
We almost lost your inquiry in the rush to discuss other stuff above.  I'm no scientist, nor have I played one on TV, but I would use a relatively thin slurry setting on Mr. malty, doing what Mark describes (a quart or so of beer left to swirl up the slurry).  Too much yeast? Yes, it seemed to create a bit of a flabby beer - not all of the qualities that come from a pitch that allows the yeast to go through its full cycle - kind of stressing it by not allowing as much reproduction as would be the case with a lesser, but adequate pitch.  I had that result with a very large pitch in a pretty modest lager wort.  You could drink it, but it was pretty much lifeless.

I do not harvest the complete contents of a fermentation vessel. I limit my thin slurry crop to 350ml (I use 500ml Erlenmeyer flasks for crops).  I limit my crop volume in order to insure that I collect the cleanest portion of the re-suspended solids.  I usually obtain between 150 and 200 milliliters of solids out of a 350ml crop.  I pitch between 100 and 150 milliliters of thick slurry, which contains approximately 1.2 billion yeast cells per milliliter for estimation purposes.

(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/YeastCrops_zps33da0025.jpg)
Title: Re: Just say "no" to yeast rinsing
Post by: ynotbrusum on May 12, 2015, 02:31:38 AM
Gotcha, Mark.

And 150 to 200 ml of relatively fresh slurry is enough to pitch directly into around a 10 gallon batch, if I recall correctly.  At least that is in the neighborhood of where I am at for ales - a bit more for lagers, perhaps.  I go to Mr. Malty based on my gravity and figure out what I need to pitch, but I try to avoid the monstrous pitch for the reason stated above.
Title: Re: Just say "no" to yeast rinsing
Post by: Whiskers on October 17, 2015, 05:40:59 AM
Great thread.  I love it when solid science is used to influence process - especially when the process ends up being easier!

In regards to the photo of the flasks with stoppers in the fridge door - one thing I've been doing for the last ten years is using a bit of foil around the top and sides of the stopper.  That way, dust is kept out of the crevice between the glass and rubber.  If there is any dust in there, some of it will likely fall into the culture before you've had a chance to flame the neck. 
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on October 19, 2015, 04:39:08 AM
If there is any dust in there, some of it will likely fall into the culture before you've had a chance to flame the neck.

I clean the area where the stopper meets the flask with an alcohol saturated cotton ball before removing the stopper.  I used to seal the area with Parafilm.

Edit:  One thing that I would like to add is that I keep my brewing refrigerator spotless because I also store my yeast bank in this refrigerator.
Title: Re: Just say "no" to yeast rinsing
Post by: jdpils on October 19, 2015, 04:05:31 PM
A lot of what S. Cerevisiae has outlined makes sense however when using a carboy or bucket for the primary, rinsing is a very practical way to reuse yeast without needing a starter.  I typically run 3 to 4 batches of beer this way.  In my experience is far more effective in separating trub and dead cells than trying to save and waste extra beer in the carboy.  I also came to the conclusion that storing in water will raise the pH.  So I have begun using lactic acid to drop the pH under 5 and also since my water has 8 ppm calcium I add 1 gm/gallon of calcium chloride.  I syphon off as much beer as appropriate to not transfer too much yeast dump water in stir and pour into a 1 gallon jug.  Fill the jug 85% about and shake.  Then let settle and pour off about 1/2 gallon of the top or middle (depends on yeast) half and store at 35F for 1 week max.  Generally I plan two days prior to brewing as some yeasts require this time to settle   When reusing I allow to warm in the garage while brewing, pour off water, pull about 1/2 gallon of wort through my CF chiller and get the slurry back on a stir plate. This thoroughly mixes the yeast and gets it going.  Then I can just pour in after chilling to the correct temp.  If I have a conical I would collect and pitch but I have not mad the transition yet.

Cheers
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on October 19, 2015, 05:04:33 PM
What makes you believe that rinsing yeast with water is the only way to directly pitch a bottom cropped culture? There is absolutely no justification for rinsing yeast with and storing it under boiled water, none.   Boiled water is not sterile, and rinsing with water adds zero value to the process. However, it does present an infection opportunity while simultaneously removing the culture's force field. Storing yeast under beer is not a waste of beer.  It is a time tested practice that is performed in most of the commercial breweries on the planet.  What you are doing is an infection in the making.  It's not a matter of if you will experience an infection.  It is merely a matter of when you will experience an infection.

By the way, storing a culture under water that is not 100% nutrient and organic matter free results in accelerated glycogen and trehalose depletion.  They only way to remove all traces of nutrients and organic matter from a cropped culture is via centrifuge.


Title: Re: Just say "no" to yeast rinsing
Post by: denny on October 19, 2015, 05:34:55 PM
A lot of what S. Cerevisiae has outlined makes sense however when using a carboy or bucket for the primary, rinsing is a very practical way to reuse yeast without needing a starter.  I typically run 3 to 4 batches of beer this way.  In my experience is far more effective in separating trub and dead cells than trying to save and waste extra beer in the carboy.  I also came to the conclusion that storing in water will raise the pH.  So I have begun using lactic acid to drop the pH under 5 and also since my water has 8 ppm calcium I add 1 gm/gallon of calcium chloride.  I syphon off as much beer as appropriate to not transfer too much yeast dump water in stir and pour into a 1 gallon jug.  Fill the jug 85% about and shake.  Then let settle and pour off about 1/2 gallon of the top or middle (depends on yeast) half and store at 35F for 1 week max.  Generally I plan two days prior to brewing as some yeasts require this time to settle   When reusing I allow to warm in the garage while brewing, pour off water, pull about 1/2 gallon of wort through my CF chiller and get the slurry back on a stir plate. This thoroughly mixes the yeast and gets it going.  Then I can just pour in after chilling to the correct temp.  If I have a conical I would collect and pitch but I have not mad the transition yet.

Cheers

Well, maybe not....I have repitched yeast that has been rinsed and yeast that has not.  There was no difference in the finished beer.  I reached the conclusion that rinsing is a lot of effort for no appreciable benefit.  Even if you don't consider it a lot of effort, there is still no benefit.  And every time you play with the yeast is another chance to contaminate it.  No, it's not a certainty...but it's a risk there is no reason to take.
Title: Re: Just say "no" to yeast rinsing
Post by: jdpils on October 19, 2015, 09:59:35 PM
I did not say rinsing is the only way to reuse yeast I stated it is a practical one.  Other than increasing the beer loss and letting settle in the carboy and pouring off the top I would be interested in hearing other options.  I used to just pour off the slurry from the primary into a 1/2 gallon mason jar.  The amount of beer lost was about 3 pints however the slurry was still dirty and I did notice that by the forth pitch I did pick up some off flavors.  By single rinsing and reusing in a short period I do not need a starter as I get about 4 to 16 oz of fairly clean paste. 
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on October 20, 2015, 02:19:01 AM
If you had three pints of liquid available for resuspending the culture, and you still achieved a dirty culture, then the problem lies in how you are cropping (more than likely coupled with how you are transferring wort from your kettle to your primary fermentation vessel).  You are not swirling the culture back into suspension, waiting for the heaviest fraction to settle, and then carefully decanting the the thinnest 350ml.  The crop shown below in the 500ml Erlenmeyer flask was cropped directly from a primary fermentation vessel using this technique.  The supernatant (clear liquid that lies above the solids) is beer.  The strain is Whitbread B, which is not the easiest strain to resuspend due to its level of flocculence (i.e., I had to swirl with a purpose in order to break up the clumps and large flocs).  This crop was taken with less than a U.S. quart of liquid left in the fermentation vessel.


(http://i699.photobucket.com/albums/vv356/tonestack/Brewing/S-04_Crop_zpsrigmrdls.jpg) (http://s699.photobucket.com/user/tonestack/media/Brewing/S-04_Crop_zpsrigmrdls.jpg.html)
Title: Re: Just say "no" to yeast rinsing
Post by: mabrungard on October 20, 2015, 12:52:16 PM
So I have begun using lactic acid to drop the pH under 5 and also since my water has 8 ppm calcium I add 1 gm/gallon of calcium chloride. 

Aren't we better off dropping the pH to something like 4? Yeast are pretty low pH tolerant, but many other organisms aren't.

Why the calcium chloride addition? Yeast do not need calcium. They need magnesium more than calcium.
Title: Re: Just say "no" to yeast rinsing
Post by: brewinhard on October 21, 2015, 11:06:46 PM
So I have begun using lactic acid to drop the pH under 5 and also since my water has 8 ppm calcium I add 1 gm/gallon of calcium chloride. 

Aren't we better off dropping the pH to something like 4? Yeast are pretty low pH tolerant, but many other organisms aren't.

Why the calcium chloride addition? Yeast do not need calcium. They need magnesium more than calcium.

If you are storing the yeast under beer as stated above, then the pH of the finished beer should be in the low 4-4.5 range shouldn't it?  Another reason to store under beer and not water.
Title: Re: Just say "no" to yeast rinsing
Post by: klickitat jim on October 22, 2015, 01:10:07 AM
I used to wash/rinse (whatever) and after getting to where I thought I had really mastered the process, I discovered that it did not help me at all. I scaled all of my recipes to 6 gallon and gave up the rinsing. The only thing I think it gains you is an extra process that adds a significant chance for infection. In my experience you loose way more than you gain. Now I just leave a little beer in the fermenter, swirl and pour to a sanitary container. On brew day I take about 100ml of the slury and make a starter. There might be a couple grams of trub in there, but trub doesn't replicate.

Most of the people I hear supporting rinsing do it because they brew super hoppy beers. Well, since you are dropping $20 on dry hops, seems like you could splurge for a fresh pitch...
Title: Re: Just say "no" to yeast rinsing
Post by: tesgüino on October 22, 2015, 12:55:06 PM
Most of the people I hear supporting rinsing do it because they brew super hoppy beers. Well, since you are dropping $20 on dry hops, seems like you could splurge for a fresh pitch...
Not in support of rinsing, but the simple answer to that is don't fear the secondary.  ;)



edit:
It's not about the money. I think I get my best beer three or more generation in.
Title: Re: Just say "no" to yeast rinsing
Post by: jdpils on October 22, 2015, 03:16:50 PM
Lots of great information here.  There is no question that yeast is better stored in beer, however getting a clean crop that can be directly repitched has been very effective for me.  I am going to retry to re-suspend my yeast slurry with the remaining beer and just dump the top third into my final container.  in the past I took the entire slurry.  Taking the top third under any liquid should resolve my issue.  If this get me to a simpler yeast crop and use I will adopt.  However considering the diameter of a carboy I am still going to pour into a 1 gallon or 1/2 gallon wide mouth container.  (If one is worried this causes contamination than one should be concerned about all their sanitation).  It would seem to me a taller vessel will facilitate better separation.  Again my goal is not to bank yeast it is to reuse without having to make a starter within one week.  For rinsing getting the pH down to 4.5 is a goal however our NW water is so soft that once any buffer is exceeded the pH will drop very fast.  Adding a little Mg may be wise too.  Also since the yeast is at the final brew pH about 4.5 with this soft water I doubt it will rise over 5 anyway.  Even if I do not treat my sparge water to 5.5, the final pH of a fully fly sparged batch is still 5.2  Our water is 30 ppm alkalinity measured as CaCO3 and .3 ppm Mg and about 1.3 sulphate the last I asked as this data is no longer published in the consumer water report.

Cheers,

Title: Re: Just say "no" to yeast rinsing
Post by: avanzandt on October 28, 2015, 07:48:39 PM
I take a different approach. Instead of messing with the stuff after the fermentation I make a 2L starter with 6 oz DME. Then pitch half in the carboy and use the pour the rest into 2 8oz canning jars. Then store it in the fridge. It has worked out fine for me, I have quite a few strains stored up and haven't had any problems.
Title: Re: Just say "no" to yeast rinsing
Post by: RPIScotty on October 28, 2015, 11:40:25 PM

I take a different approach. Instead of messing with the stuff after the fermentation I make a 2L starter with 6 oz DME. Then pitch half in the carboy and use the pour the rest into 2 8oz canning jars. Then store it in the fridge. It has worked out fine for me, I have quite a few strains stored up and haven't had any problems.

But then you miss out on repitching.


Sent via Tapatalk
Title: Re: Just say "no" to yeast rinsing
Post by: S. cerevisiae on October 29, 2015, 04:01:17 AM
I take a different approach. Instead of messing with the stuff after the fermentation I make a 2L starter with 6 oz DME. Then pitch half in the carboy and use the pour the rest into 2 8oz canning jars. Then store it in the fridge. It has worked out fine for me, I have quite a few strains stored up and haven't had any problems.

You are missing out on the advantages of repitching.  Repitching requires no starter, and a culture tends to perform better on a repitch. 

Liquid cultures are okay for short-term storage, but you will end up with diminished fermentation performance over time.  If you want to keep a more stable yeast bank, you should look into slants.   I maintain all of my cultures on slant.   I have maintained cultures for years on slant, that is, when I remembered to perform periodic subculturing.   The beauty of keeping yeast on slant after going through single-cell isolation on a plate is that slant-to-slant transfers are performed using absolutely sterile media under sterile conditions; hence, the culture remains pure.
Title: Re: Just say "no" to yeast rinsing
Post by: hopfenundmalz on October 29, 2015, 02:21:15 PM
Most of the people I hear supporting rinsing do it because they brew super hoppy beers. Well, since you are dropping $20 on dry hops, seems like you could splurge for a fresh pitch...
Not in support of rinsing, but the simple answer to that is don't fear the secondary.  ;)



edit:
It's not about the money. I think I get my best beer three or more generation in.
There are those (not here so much) that say you will contaminate your beer if you do a secondary, then go on about making starters and rinsing/washing their yeast as if those steps are exempt from contamination.

I don't rinse. I have captured yeast from the conical for a repitch, and have made many a beer using the yeast cake in a carboy.
Title: Re: Just say "no" to yeast rinsing
Post by: kbenton00 on October 29, 2015, 07:32:09 PM
I agree with Joe Sr.... I like the Old Raspy in the fridge.  My local alehouse just started tapping this year's BBA Old Rasputin... yummy :).  Though to be honest I preferred last years BBA.