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General Category => Yeast and Fermentation => Topic started by: klickitat jim on June 08, 2013, 12:59:37 AM

Title: Basic Yeast Questions
Post by: klickitat jim on June 08, 2013, 12:59:37 AM
I think I've been under pitching. As you know I bought a couple stir plates recently and I'm learning about that. I bought the Mr Malty app and figured out how to work that. I've watched a few wyeast and white labs videos. ..

1. Lets say I run a 2000ml starter for 24 hrs, then put the flask in the fridge to settle the yeast. How long can it sit in the fridge before decant and pitch? Would 3 or 4 days have much effect?

2. When washing and repitching from a previous brew, how do you estimate and measure how much of that to pitch. A low tech method would be awesome. How long can the washed yeast last in the fridge? Can you use the same viability rates as the smack packs, like about 30% loss per month?

3. Generally speaking, how do ester and fusel production relate to fermentor temp and pitch rate?

I'm asking these questions to verify my understanding. Here's what I think.

1. I think a starter would be just fine in the fridge for a few days, but after a week or so you begin losing viability.

2. I think if you wash a yeast cake right away and keep it in the fridge, it's good for a few days before viability loss starts. I personally wouldn't use it as-is past a month. I think for an <1.060 ale I would use a half cup slurry. Double for a lager or high gravity ale.

3. I think that low pitch rate encourages growth and therefore less esters and more off flavors. High pitch rate increases ester, decreases off flavor except if your over pitch leads to Autolysis. I think fermenting at the low end of the yeasts temp range reduces esters but risks off flavors from poor fermentation. Fermenting at the high end increases esters but risks high fusel production.

Am I on track?  Set me straight please
Title: Re: Basic Yeast Questions
Post by: travjohn92 on June 08, 2013, 01:08:44 AM
I can't speak to 2 and 3, but I see know reason to put the starter in the fridge to settle the yeast.  When I make my starters, I make them first thing in the morning and then pitch it at the end of the day (10-15 hour mark).  You are going to swirl the yeast before dumping into the wort anyway.  I usually make a 1.5 or 2 liter starter and have never had any issues.
Title: Re: Basic Yeast Questions
Post by: thebigbaker on June 08, 2013, 01:38:40 AM
1.  I've left yeast in the fridge 2 days once before and didn't notice any difference from when I left in in there overnight or the same day.  I don't think the difference in viability from 1 - 3 days makes much difference on a homebrew level.  As mentioned by travjohn above, I don't always cool and decant my starters.  It really just depends on the beer.  If I'm making a lower gravity beer, I may decant.  If it's a bigger, darker beer, I just throw it all in.  I've done this each way with an American Wheat beer and I couldn't tell a difference.

2.  Mr. Malty can help determine how much slurry from washed yeast to use.  Select the "repitching from slurry" tab and I usually slide the "yeast concentration" slider closer towards the "Thick Yeas" side since I will decant most of the liquid.  When I wash my yeast, I usually store it into 4 different mason jars which have ml readings making it easy to estimate the amount of yeast in each jar.  Depending on how much I will be using over the next week or two, I will either take a jar and make a starter or just throw in 2 jars, which usually will have 40 - 60ml of yeast slurry.  With Mr. Malty, play with the "Harvest Date" in the "Repitching from Slurry" section to see how time changes the viability of the slurry. 

3.  As far as I know, you are correct with pitch rates with ester/ fusel production.  Less yeast increases the ester/fusel production along with more diacetyl, which depending on the beer is what you may want.  Higher pitch rates is less ester/ fusel.  Fermenting on the lower side of the temp scale I think does help reduce esters, but I don't think you risk off flavors from poor fermentation.  You may risk stuck fermentation if it gets too low, but I don't think it throws off flavors other than maybe a less drier beer.  Ferment too high and you are in danger of some bad fusel production for sure.

I don't consider myself a yeast expert, so please if I'm wrong with any of this feel free to correct me. 
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 08, 2013, 01:57:43 AM
Thanks for pointing out the repitch feature. Assuming I rack a beer and wash the yeast to repitch one week later, using the middle setting on concentration and trube percentage, it shows I need 100ml for a 1.060 ale. That's just shy of a half cup. So I guess my knowledge was right on that one. I'm learning from you guys!

Per Mr Malty, repitch is 95% viable new, 75% at a month, and 50% at two months, and 33% at three months. So about the same viability as a smack pack. Personally I won't be holding used yeast more than a couple weeks.
Title: Re: Basic Yeast Questions
Post by: a10t2 on June 08, 2013, 05:13:49 PM
If the yeast has been settling for a week, it will compact to 3-4 billion cells per mL. So for a 1.060 ale you'd want to pitch around 60 mL (1/4 cup).
Title: Basic Yeast Questions
Post by: denny on June 08, 2013, 05:19:59 PM
Bigbaker, current theory is less yeast decreases ester production, not increases it.  Both Clayton Cone of Lallemand and Neva Parker of White have talked about that. The same enzyme is responsible for cell growth and ester production and wheit does one it doesn't do the other.  So, when you pitch less yeast, the enzyme is bust with cell growth and ester production is reduced.
Title: Re: Basic Yeast Questions
Post by: thebigbaker on June 08, 2013, 07:36:37 PM
Bigbaker, current theory is less yeast decreases ester production, not increases it.  Both Clayton Cone of Lallemand and Neva Parker of White have talked about that. The same enzyme is responsible for cell growth and ester production and wheit does one it doesn't do the other.  So, when you pitch less yeast, the enzyme is bust with cell growth and ester production is reduced.

Thanks Denny,  I just went back and looked at Neva's presentation PDF from last year and she does state that lower yeast count decreases esters and higher increases them.  I could have sworn that I read on White Labs or Wyeast's website somewhere that esters increased with lower yeast pitch rates.  To prove to myself that I wasn't crazy, I just went to each site and Wyeast does state the opposite, with lower pitch rate = increased esters and vice versa.  http://www.wyeastlab.com/com-pitch-rates.cfm (http://www.wyeastlab.com/com-pitch-rates.cfm) 

I know Neva Parker's presentation was just last year (thanks AHA for putting these presentations online for those of us who couldn't make the conference!), so is the less yeast = less ester theory relatively new?  I'll search and see what Clayton has to say on the subject. 
Title: Basic Yeast Questions
Post by: denny on June 08, 2013, 07:59:03 PM
I can post a link to Dr. Cone's info on the Lallemand website tomorrow if you haven't found it by then.
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 09, 2013, 02:00:47 AM
That would be great Denny
Title: Re: Basic Yeast Questions
Post by: a10t2 on June 09, 2013, 02:29:08 AM
I think this is what you're looking for: http://www.danstaryeast.com/articles/lager-pitching-temperatures

That whole Articles section of their site is worth bookmarking.
Title: Re: Basic Yeast Questions
Post by: denny on June 09, 2013, 05:14:08 PM
This is the one I had in mind.

http://www.danstaryeast.com/articles/yeast-growth
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 09, 2013, 08:12:38 PM
Thanks!
Title: Re: Basic Yeast Questions
Post by: thebigbaker on June 09, 2013, 08:56:53 PM
Thanks for the links.  Wonder why there is different opinions w/ Wyeast stating that lower pitch rates = increase ester production and others are stating the opposite.  Maybe I'll email Wyeast to explain their view and present to them some of the opposing views on this issue. 
Title: Re: Basic Yeast Questions
Post by: joe_feist on June 09, 2013, 11:51:49 PM
I checked my copy of Chris White's "Yeast" since Wyeast came up. He says in the book-
1. Storage up to two weeks is probably best. The sooner the better. Made sense to me.
2. From page 121, under pitching effects flavor more and over pitching has a bigger impact on health. It all apperears relative, though, because both over/under pitching can effect flavor with high levels of diacetyl and acetlaldehyde.
His biggest point, IMHO, is when says to measure your yeast best you can, find what works with your beer and then be consistent.

Trying to be consistent was probably the only point that made sense to me.

Title: Re: Basic Yeast Questions
Post by: ynotbrusum on June 10, 2013, 01:35:17 AM
What about the Hefeweizen and Belgian idea of intentionally under pitching to produce the esters?
Title: Re: Basic Yeast Questions
Post by: HoosierBrew on June 10, 2013, 01:48:28 AM
What about the Hefeweizen and Belgian idea of intentionally under pitching to produce the esters?
+1.  Always my understanding too.
Title: Re: Basic Yeast Questions
Post by: denny on June 10, 2013, 04:35:11 PM
What about the Hefeweizen and Belgian idea of intentionally under pitching to produce the esters?

My understanding is that these strains do [produce more esters by underpitching, but the whole issue is so nebulous I wouldn't say for certain.
Title: Re: Basic Yeast Questions
Post by: a10t2 on June 10, 2013, 05:22:35 PM
What about the Hefeweizen and Belgian idea of intentionally under pitching to produce the esters?

I've never seen a controlled study suggesting that's actually the case. (Actually, I'm getting ready to start one with a Belgian strain, but I don't have an HPLC, so it will be totally subjective.)
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 10, 2013, 07:20:19 PM
It's sounding like these may be basic yeast question but there are few basic yeast answers. I will wrap my mind around this eventually though.
Title: Re: Basic Yeast Questions
Post by: denny on June 10, 2013, 07:22:58 PM
What about the Hefeweizen and Belgian idea of intentionally under pitching to produce the esters?

I've never seen a controlled study suggesting that's actually the case.

Agreed.  AFAIK, it's anecdotal.
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 10, 2013, 09:26:26 PM
I'm way green to the hobby/science but it seems to me that very little of this is settled law.
Title: Re: Basic Yeast Questions
Post by: joe_feist on June 10, 2013, 10:05:14 PM
I think it's as much art as science, so I'd agree it's not settled law. I seem to run into as many different opinions as there are posters out there (and books, too).

It's pretty fun, really, to work through this and see what happens. We all have different set-ups (equipment), recipes, yeasts, environments, yadda, yadda, yadda...

So, I believe there's general agreement that yeast used the fresher the better. The merits of under pitching versus over pitching seems to be a matter of debate. I will say that I thought the yeast strains themselves were responsible for the unique flavors of weizens versus deliberately under pitching. I don't know if that's right or wrong, I'm just saying I never considered that as a variable. Something to think about.
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 10, 2013, 10:38:37 PM
I have no doubt that I am at the beginning of the learning curve. I think I have the basics (do this or you won't make decent beer) down pat. But as far as the rest? Just getting started.

I've said this before but, I think brewing is one of those things where sometimes you read something as fact and it ain't so. Doctor Palmers first edition HTB for example. Its a great starting point, but a lot of the deep stuff is up for discussing. That said, he knows way way more than me.

Yeast, they are our friends. Be kind and they will reward you.
Title: Re: Basic Yeast Questions
Post by: denny on June 10, 2013, 10:49:56 PM
Jim, I think the key is read a lot.  When you read something that seems to make sense from a person who seems to know what (s)he's talking about, try it and see if it works for you.  Repeat often.
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 10, 2013, 11:27:22 PM
Bingo! Well said.

I also think that years brewing doesn't always equate to experience expertise or knowledge. In my profession I know several with multiple years of repeating the same thing they learned the first six months. We call them retired on duty lol.

Thanks entirely to this forum, Denny in particular,  I feel I've learned as much as a vet home brewer in just a couple months.
Title: Re: Basic Yeast Questions
Post by: ynotbrusum on June 11, 2013, 02:39:02 AM
Bingo! Well said.

Thanks entirely to this forum, Denny in particular,  I feel I've learned as much as a vet home brewer in just a couple months.

It allows you to learn from the mistakes of others, because Lord knows I make some anyway, I might as well miss a few on the way!  Some really good info here, for sure....
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 11, 2013, 02:44:49 AM
Totally!  I remember about 1990 a guy i worked with home brewed. His stuff rocked. I thought. But wow things have changed
Title: Re: Basic Yeast Questions
Post by: aschecte on June 11, 2013, 04:37:36 AM
I think I've been under pitching. As you know I bought a couple stir plates recently and I'm learning about that. I bought the Mr Malty app and figured out how to work that. I've watched a few wyeast and white labs videos. ..

1. Lets say I run a 2000ml starter for 24 hrs, then put the flask in the fridge to settle the yeast. How long can it sit in the fridge before decant and pitch? Would 3 or 4 days have much effect?

2. When washing and repitching from a previous brew, how do you estimate and measure how much of that to pitch. A low tech method would be awesome. How long can the washed yeast last in the fridge? Can you use the same viability rates as the smack packs, like about 30% loss per month?

3. Generally speaking, how do ester and fusel production relate to fermentor temp and pitch rate?

I'm asking these questions to verify my understanding. Here's what I think.

1. I think a starter would be just fine in the fridge for a few days, but after a week or so you begin losing viability.

2. I think if you wash a yeast cake right away and keep it in the fridge, it's good for a few days before viability loss starts. I personally wouldn't use it as-is past a month. I think for an <1.060 ale I would use a half cup slurry. Double for a lager or high gravity ale.

3. I think that low pitch rate encourages growth and therefore less esters and more off flavors. High pitch rate increases ester, decreases off flavor except if your over pitch leads to Autolysis. I think fermenting at the low end of the yeasts temp range reduces esters but risks off flavors from poor fermentation. Fermenting at the high end increases esters but risks high fusel production.

Am I on track?  Set me straight please
On part 1 I think your probably pretty solid though I make my starters the day before I brew which is usually on Sunday so mid day Friday I begin my starter and by Saturday night it's in the keezer dropping that yeast from suspension on Sunday decant and pitch. I think your fine from everything I have read for a few days and your probably on target for that 1 week loss of viability.

#2 I don't save cakes though others do and could give better advice though I do rack fresh wort onto a cake so it a bit of a PITA as my brew partner is kegging a beer during the last hour of brewing ( sanitizing the keg racking cane hoses etc and the actual transfer) we usually leave just enough beer to keep the cake barely covered and then cover the carboy back up with a sanitized bung and airlock. once the fresh wort is chilled to temp onto the cake the fresh wort goes. I have read of people collecting the cake and using for up to a week.
 
#3 and I could be way off but I think I'm on target a low pitch rate causes more esters as they are a by product of the growth phase and a low pitch rate can also cause off flavors. A high pitch rate will cause off flavors fusel alcohol and is IMHO worse than under pitching. I would recommend doing neither pitch the proper amount or if reusing a cake try to match the OG of the previous beer to the new OG as close as possible as then you are only bypassing the reproductive and growth phase and just going straight into straight up chomping on sugar phase.

hope that helps but if anyone with more experience disagrees please also set me straight.
Title: Re: Basic Yeast Questions
Post by: denny on June 11, 2013, 05:07:56 PM
I could be way off but I think I'm on target a low pitch rate causes more esters as they are a by product of the growth phase and a low pitch rate can also cause off flavors.

Take another look at the info from Clayton Cone and Neva Parker in this thread.  There's persuasive evidence that higher pitch rates create more esters.
Title: Re: Basic Yeast Questions
Post by: aschecte on June 11, 2013, 05:51:16 PM
I could be way off but I think I'm on target a low pitch rate causes more esters as they are a by product of the growth phase and a low pitch rate can also cause off flavors.

Take another look at the info from Clayton Cone and Neva Parker in this thread.  There's persuasive evidence that higher pitch rates create more esters.
Denny as you know I'm kinda new here and not to sound like an idiot but I don't see anyone with those names in this thread....... are you using their real names? it sounds like they are... I can't see that is there a option for this somewhere if this is the case ?
Title: Re: Basic Yeast Questions
Post by: aschecte on June 11, 2013, 05:53:45 PM
disregard I see what your referring to..... the link... going to read it right now.
Title: Re: Basic Yeast Questions
Post by: denny on June 11, 2013, 09:28:31 PM
Glad ya found it!
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 11, 2013, 11:45:01 PM
I think pitch rate and fermentor temp can vary type of ester too. Seems like under pitch brings banana and over brings clove, read that somewhere
Title: Re: Basic Yeast Questions
Post by: hopfenundmalz on June 11, 2013, 11:53:06 PM
I think pitch rate and fermentor temp can vary type of ester too. Seems like under pitch brings banana and over brings clove, read that somewhere
Clove is from phenolics, not esters.
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 12, 2013, 12:41:31 AM
Ah ha. Thanks!
Title: Re: Basic Yeast Questions
Post by: aschecte on June 12, 2013, 02:48:21 AM
I could be way off but I think I'm on target a low pitch rate causes more esters as they are a by product of the growth phase and a low pitch rate can also cause off flavors.

Take another look at the info from Clayton Cone and Neva Parker in this thread.  There's persuasive evidence that higher pitch rates create more esters.
   Just a FYI I read the links and it actually supports what I wrote about low pitch rates creating higher ester production though I was wrong abut the fusel alcohol which I thought was created with higher pitching rates.  I copied the article and will paste below

Effect of Pitch Rate on Beer Flavor

Pitch rates, in addition to strain, temperature, and gravity, make a dramatic difference in the final flavor and aroma profile of any beer.  The pitch rate will have a direct effect on the amount of cell growth during a fermentation.  Cell growth decreases as pitch rates increase. Ester production is directly related to yeast growth as are most other flavor and aroma compounds.
A low pitch rate can lead to: •Excess levels of diacetyl
•Increase in higher/fusel alcohol formation
•Increase in ester formation
•Increase in volatile sulfur compounds
•High terminal gravities
•Stuck fermentations
•Increased risk of infection
High pitch rates can lead to: •Very low ester production
•Very fast fermentations
•Thin or lacking body/mouthfeel
•Autolysis (Yeasty flavors due to lysing of cells)
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 12, 2013, 03:01:52 AM
What I have learned from this thread is that I have been under pitching. Now fixed with my stir plates. I'll be aiming at PROPER pitch rates and erring on the slightly over pitch side if anything.
Title: Re: Basic Yeast Questions
Post by: thebigbaker on June 12, 2013, 03:08:37 AM
I could be way off but I think I'm on target a low pitch rate causes more esters as they are a by product of the growth phase and a low pitch rate can also cause off flavors.

Take another look at the info from Clayton Cone and Neva Parker in this thread.  There's persuasive evidence that higher pitch rates create more esters.
   Just a FYI I read the links and it actually supports what I wrote about low pitch rates creating higher ester production though I was wrong abut the fusel alcohol which I thought was created with higher pitching rates.  I copied the article and will paste below

Effect of Pitch Rate on Beer Flavor

Pitch rates, in addition to strain, temperature, and gravity, make a dramatic difference in the final flavor and aroma profile of any beer.  The pitch rate will have a direct effect on the amount of cell growth during a fermentation.  Cell growth decreases as pitch rates increase. Ester production is directly related to yeast growth as are most other flavor and aroma compounds.
A low pitch rate can lead to: •Excess levels of diacetyl
•Increase in higher/fusel alcohol formation
•Increase in ester formation
•Increase in volatile sulfur compounds
•High terminal gravities
•Stuck fermentations
•Increased risk of infection
High pitch rates can lead to: •Very low ester production
•Very fast fermentations
•Thin or lacking body/mouthfeel
•Autolysis (Yeasty flavors due to lysing of cells)

This is from the Wyeast site that I linked earlier in the thread.  However, Neva Parker's presentation from last year's AHA conference (which you can find on this site) and the links above for Clayton Clone's articles show evidence of low pitch rate = lower esters and vice versa.  Who's right, I don't know.  However, as Jim states, proper pitch rates is my goal and I don't think that if you slightly under or over pitch it's going to make that big of a difference on a homebrew level...at least that's what I've been told.
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 12, 2013, 03:41:09 AM
My general practice is going to be
Wyeast fresh as possible (less than a month)
2000ml starters with 1.030-40
16-24hrs on stir plate then cold crash in fridge, use within 3-4 days
For ales <1.065 one starter
For lagers or ales >1.065 I'll use two smack packs in two starters

I reserve the right to learn and adjust in the future lol.
Title: Re: Basic Yeast Questions
Post by: aschecte on June 12, 2013, 04:47:34 PM
I could be way off but I think I'm on target a low pitch rate causes more esters as they are a by product of the growth phase and a low pitch rate can also cause off flavors.

Take another look at the info from Clayton Cone and Neva Parker in this thread.  There's persuasive evidence that higher pitch rates create more esters.
   Just a FYI I read the links and it actually supports what I wrote about low pitch rates creating higher ester production though I was wrong abut the fusel alcohol which I thought was created with higher pitching rates.  I copied the article and will paste below

Effect of Pitch Rate on Beer Flavor

Pitch rates, in addition to strain, temperature, and gravity, make a dramatic difference in the final flavor and aroma profile of any beer.  The pitch rate will have a direct effect on the amount of cell growth during a fermentation.  Cell growth decreases as pitch rates increase. Ester production is directly related to yeast growth as are most other flavor and aroma compounds.
A low pitch rate can lead to: •Excess levels of diacetyl
•Increase in higher/fusel alcohol formation
•Increase in ester formation
•Increase in volatile sulfur compounds
•High terminal gravities
•Stuck fermentations
•Increased risk of infection
High pitch rates can lead to: •Very low ester production
•Very fast fermentations
•Thin or lacking body/mouthfeel
•Autolysis (Yeasty flavors due to lysing of cells)

This is from the Wyeast site that I linked earlier in the thread.  However, Neva Parker's presentation from last year's AHA conference (which you can find on this site) and the links above for Clayton Clone's articles show evidence of low pitch rate = lower esters and vice versa.  Who's right, I don't know.  However, as Jim states, proper pitch rates is my goal and I don't think that if you slightly under or over pitch it's going to make that big of a difference on a homebrew level...at least that's what I've been told.

Agreed Who is right ? IDK either from my experience I have zero input because I always properly pitch so it has never been a issue for me. That said bottom line who cares about the effect of over or under pitching ? Just do it right and get a good beer in the end.
Title: Re: Basic Yeast Questions
Post by: hopfenundmalz on June 12, 2013, 05:16:20 PM
I have not been able to get the right fruity aromas in my TTL clone. The last time was a 25% over pitch. Next time will be under pitched if that does the trick.


Title: Re: Basic Yeast Questions
Post by: denny on June 12, 2013, 05:39:00 PM
I definitely started finding my beers cleaner when I stopped using the entire slurry from a previous batch and started using only 1/3-1/2 of the slurry.  So, in a way, I found my own proof.
Title: Re: Basic Yeast Questions
Post by: DrewG on June 12, 2013, 07:30:20 PM
Quote
My general practice is going to be
Wyeast fresh as possible (less than a month)
2000ml starters with 1.030-40
16-24hrs on stir plate then cold crash in fridge, use within 3-4 days
For ales <1.065 one starter
For lagers or ales >1.065 I'll use two smack packs in two starters

I reserve the right to learn and adjust in the future lol.

I just use the calculator. For instance, for a 1.055 ale with a 3 week old vial you'd only need a 1L starter on a plate to produce the 211 billion cells you need in a 5.5 gallon ferment. Saves on the DME, too.
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 12, 2013, 09:40:34 PM
I hear ya, but the white labs lady says 1000ml is waste of time
Title: Re: Basic Yeast Questions
Post by: joe_feist on June 12, 2013, 11:13:36 PM
;)
I definitely started finding my beers cleaner when I stopped using the entire slurry from a previous batch and started using only 1/3-1/2 of the slurry.  So, in a way, I found my own proof.

I think that's right and is in line with what Chris White says in his book. Find what works in your system and be consistent. Adjust from there. Honestly, I don't know that I could compare "half the slurry" in your system to mine... As we're probably 1,000 miles apart and I've never had the privelage.
I also think Jim's process is a great place to start and I'll probably steal it...but don't tell any body ;)
Title: Re: Basic Yeast Questions
Post by: klickitat jim on June 13, 2013, 12:34:48 AM
Go for it. I'm just trying to understand the details but then use a simple method that does the job. I might fiddle with it in certain styles to boost esters but if I do it will be from understanding rather than lack of or accident
Title: Re: Basic Yeast Questions
Post by: a10t2 on June 13, 2013, 03:17:52 PM
I hear ya, but the white labs lady says 1000ml is waste of time

For what it's worth, the numbers from the NHC presentation are *much* lower than what I see in 1 L starters. I've found that 100 billion cells per liter of 8°P wort (stirred) gets me within 30% every time.

Now I wish I'd gone to that seminar instead of whichever one I picked instead... It would be nice to have all the parameters of Neva Parker's experiments.
Title: Re: Basic Yeast Questions
Post by: denny on June 13, 2013, 03:46:10 PM
I hear ya, but the white labs lady says 1000ml is waste of time

She's not the only one.  My understanding is that if you make the starter too small there's not enough food for the yeast to rebuild their glycogen reserves  DISCLAIMER:  I am not a biochemist!
Title: Re: Basic Yeast Questions
Post by: DrewG on June 13, 2013, 04:19:14 PM
Sean, just to clarify, you're saying 100 billion cells in an 8p 1 liter starter is getting you within 30 percent of desired pitching rate?
Title: Re: Basic Yeast Questions
Post by: a10t2 on June 13, 2013, 06:55:19 PM
Yeah, that wasn't at all clear... 100 of growth, ~200 billion total from a pack in a 1 L starter.