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General Category => Yeast and Fermentation => Topic started by: petermmitchell on August 13, 2017, 04:29:33 pm

Title: Reusing 34/70 dry lager yeast
Post by: petermmitchell on August 13, 2017, 04:29:33 pm
I read somewhere that reusing dry yeast was not recommended, but wanted to see if others had any experience with reusing 34/70.  I have a 5 gal batch of pilsner fermented with 34/70 that I would like to repitch into a larger 10gal batch of Oktoberfest.  I was planning to pitch half of the yeast cake into each 5 gallon batch of the Oktoberfest. I am using 2 buckets for the 10 gal batch.  Any issues with doing this?
Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on August 13, 2017, 04:35:55 pm
Never had a problem reusing any dry yeast.
Title: Reusing 34/70 dry lager yeast
Post by: BrewBama on August 13, 2017, 05:54:46 pm
I read on one of the dry yeast mfrs sites that they recommend it not be reused.

Here it is: http://www.fermentis.com/brewing/homebrewing/frequently-asked-questions/

Can I re-use the yeast?
Due to the risks of infection and the inability to check yeast cell counts of yeast slurries it is not recommended as the risk of failure is increased and outweighs the cost of new yeast.

Edit: But the Danstar tech data sheet for London ESB says "When using Lallemand Brewing Yeasts, you may repitch the yeast just as you would any other type of yeast according to your brewery’s SOP for yeast handling."  LOL

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Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on August 13, 2017, 06:01:34 pm
I read on one of the dry yeast mfrs sites that they recommend it not be reused.

Here it is: http://www.fermentis.com/brewing/homebrewing/frequently-asked-questions/

Can I re-use the yeast?
Due to the risks of infection and the inability to check yeast cell counts of yeast slurries it is not recommended as the risk of failure is increased and outweighs the cost of new yeast.

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which are exactly the same concerns with reusing any yeast, liquid or dry.  Dry yeast is not more prone to those issues than liquid, yet we reuse liquid yeast all the time.
Title: Re: Reusing 34/70 dry lager yeast
Post by: natebrews on August 13, 2017, 06:11:13 pm
Wasn't it, once upon a time, that dry cultures weren't pure cultures (something to do with the drying method) and so they weren't suitable for use over many propagations?  I don't imagine this is the case anymore, but I'm wondering if this is some bit of knowledge that has lasted beyond its relevancy. 
Title: Re: Reusing 34/70 dry lager yeast
Post by: BrewBama on August 13, 2017, 06:27:33 pm
I read on one of the dry yeast mfrs sites that they recommend it not be reused.

Here it is: http://www.fermentis.com/brewing/homebrewing/frequently-asked-questions/

Can I re-use the yeast?
Due to the risks of infection and the inability to check yeast cell counts of yeast slurries it is not recommended as the risk of failure is increased and outweighs the cost of new yeast.

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which are exactly the same concerns with reusing any yeast, liquid or dry.  Dry yeast is not more prone to those issues than liquid, yet we reuse liquid yeast all the time.

I even read lager yeast shouldn't be reused because it absorbs DMS in the fermentation D rest so when reused could increase the chance of DMS in the new brew. If it's on the internet it has to be true right?  (I read '6 myths' on AHA by Denny last night.)


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Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on August 13, 2017, 06:55:08 pm
I read on one of the dry yeast mfrs sites that they recommend it not be reused.

Here it is: http://www.fermentis.com/brewing/homebrewing/frequently-asked-questions/

Can I re-use the yeast?
Due to the risks of infection and the inability to check yeast cell counts of yeast slurries it is not recommended as the risk of failure is increased and outweighs the cost of new yeast.

Sent from my iPhone using Tapatalk

which are exactly the same concerns with reusing any yeast, liquid or dry.  Dry yeast is not more prone to those issues than liquid, yet we reuse liquid yeast all the time.

I even read lager yeast shouldn't be reused because it absorbs DMS in the fermentation D rest so when reused could increase the chance of DMS in the new brew. If it's on the internet it has to be true right?  (I read '6 myths' on AHA by Denny last night.)


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well, I don't do a d rest, so I guess I'm OK!  ;)
Title: Re: Reusing 34/70 dry lager yeast
Post by: petermmitchell on August 13, 2017, 07:41:43 pm
Hey that's why this forum is needed.  We can learn and change our misconceptions :)  Thanks for your advice!
Title: Re: Reusing 34/70 dry lager yeast
Post by: Bob357 on August 14, 2017, 12:29:08 am
I generally keep a pack or 2 of US-05 in my yeast fridge just in case. I recently found myself with only that for ale yeast and one packet was dated. Didn't have any reason to use it for quite some time. The second packet was getting close to 2 years old, so I rehydrated it and then pitched it into a starter to produce a couple of 100B cell vials. I used these vials as I would fresh liquid yeast and they performed well. While I use mostly English ale yeasts for my APAs and IPAs, I haven't found a dry English ale yeast that I prefer over the liquid offerings.

Not sure if first rehydrating is necessary when making a starter from dry yeast, but I prefer to err on the side of caution. IMHO, today's dry yeasts are of a quality comparable to liquids. As for re-use, US-05 is reputed to perform much better when re-using than on the first pitch. 
Title: Re: Reusing 34/70 dry lager yeast
Post by: GolfBum on August 14, 2017, 01:13:27 pm
I have started using 34/70 for my lagers this summer and have saved the yeast and it is going on it's 4th batch. I don't see any negatives to saving it and reusing. In fact I think the fermentation has gotten stronger as the generations move forward. The first batch fermented well but the second and third batches had shorter lag times, and seemed to ferment well. The beers tasted amazing too. I only plan to use a couple more times before I start over with some new packs though.
Title: Re: Reusing 34/70 dry lager yeast
Post by: MerlinWerks on August 14, 2017, 02:27:02 pm
I just pitched an 8th generation slurry from two packs of 34/70 that I re-hydrated at the beginning of the year. I'll probably go two more and start over.
Title: Re: Reusing 34/70 dry lager yeast
Post by: reverseapachemaster on August 14, 2017, 03:18:32 pm
I've repitched slurry from both US-05 and 34/70 with no problems.

Fermentis's position is one part an unspecific statement of fact (repitching yeast always invites risk of infection) and one part straight marketing (it's cheaper to buy new yeast). Put them together it's just advising you to buy more of their product.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Brew Cat on August 15, 2017, 02:06:20 am
Of course the manufacturer says don't repitch.  I've actually found 34/70 works better when repitching. I'll start my lager series in November and keep repitching until March. I've done this for 3 seasons and haven't noticed any difference pitch to pitch

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Title: Re: Reusing 34/70 dry lager yeast
Post by: el_capitan on August 18, 2017, 04:44:53 am
Man, I'm always amazed at how this forum supports my brewing.  Right now I'm cold-crashing an O-fest, with plans to repitch the 34/70 into a Munich Dunkel tomorrow.  I think that as long as the initial fermentation was clean and healthy, the slurry should be in better shape than the original dry pack.  Maybe I'm vastly oversimplifying things here. 

One thing that I recently picked up here was the idea of overbuilding starters in order to maintain a cleaner yeast culture.  I've been using that method a lot in my brewing, and I like it a lot.  So, the downside with repitching is the gamble of contamination.  I plan to reserve a clean portion of my yeast slurry from the Ofest as my "pure" culture, and then build that through starters for future lagers. 

However, a whole batch worth of lager slurry is way to valuable to just dump, so I see myself overbuilding a starter, brewing a batch, then using the slurry for a second batch or two.  I don't brew lagers that often, but I'm definitely going to keep moving forward with this method as a way to simplify lager production. 

PS - doesn't dry yeast pretty much turn to liquid once you use it?   ;)
Title: Re: Reusing 34/70 dry lager yeast
Post by: ynotbrusum on August 24, 2017, 12:14:07 am
I have gone to using dry yeast in the summer months and not repitching during the summer due to a concern that there is just a higher degree of airborne contaminants during the warm months, so any collection and repitching is more perilous in the summer. Probably overkill, though, because if you pitch enough yeast it should outcompete a minor infection, right?  I just try to minimize the chances of an infection.  Also I have found that I really like S-189, so it is pretty easy peasy to use that for my lagers without needing to repitch.
Title: Re: Reusing 34/70 dry lager yeast
Post by: doc280 on November 06, 2020, 11:47:14 pm
I know this is an old thread, however it almost had all the information I required. When harvesting 34/70 and then when it is time to pitch, does one use half or the entire amount of the harvested yeast. I know ale yeast it is about half, just not sure about lager yeast.
Title: Re: Reusing 34/70 dry lager yeast
Post by: HopDen on November 07, 2020, 01:15:22 pm
I know this is an old thread, however it almost had all the information I required. When harvesting 34/70 and then when it is time to pitch, does one use half or the entire amount of the harvested yeast. I know ale yeast it is about half, just not sure about lager yeast.

That depends on what you are making. 34/70 is a lager yeast so I will comment on using it for a lager recipe. Use all of it, making sure you have the proper pitch rate. I personally don't worry about that when repitching. Pour most of the beer off, swirl the remaining and pitch. I have gone, if I remember correctly, 6-7 generations with 34/70 without any perceptual difference. I also will pitch straight from the cooler. No need to let it warm up.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 07, 2020, 09:33:54 pm
You want to pitch around 150ml of settled, thick slurry per five gallons of wort, especially if you plan to serially repitch a culture.  Underpitching is okay.  Overpitching leads to insufficient new cell growth to sustain a culture over multiple repitches.
Title: Re: Reusing 34/70 dry lager yeast
Post by: majorvices on November 08, 2020, 11:23:24 am
I know this is an old thread, however it almost had all the information I required. When harvesting 34/70 and then when it is time to pitch, does one use half or the entire amount of the harvested yeast. I know ale yeast it is about half, just not sure about lager yeast.

I find the yeast picthing calculators handy and convenient. Gives you an idea how much yeast you need for every batch. http://www.mrmalty.com/calc/calc.html

I have counted counted cells with a microscope and hemocytometer and matched it very closely with these results.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 08, 2020, 01:58:37 pm
I find the yeast picthing calculators handy and convenient. Gives you an idea how much yeast you need for every batch. http://www.mrmalty.com/calc/calc.html

I have counted counted cells with a microscope and hemocytometer and matched it very closely with these results.

I have also counted stained yeast cells using an hemocytometer and a microscope. It is an interesting exercise and necessary for commercial brewing, but has limited use at home.  At this point, I really do not find yeast calculators to be all that useful.  I find rules of thumb combined with my experience with a culture to be more useful.  That being said, what is interesting is that Mr. Malty's standard re-pitch suggestion is 173ml, which is basically a 1L starter at maximum cell density. His ale pitching rate is 500ml at maximum cell density, which solidifies my assertion that underpitching by as much as 50% makes no difference in fermentation outcome while providing enough new cell growth that a culture can be serially re-pitched more than a couple of times without worrying about a huge loss in viability, that is, as long as one's wort is well aerated.   I have always re-pitched between 150 and 175ml of settled slurry per 5.25 gallons.  That is based in the rule of thumb that 1ml of settled, thick slurry contains approximately 1.2 billion cells as well as the accepted average maximum cell density of a 1L starter, which is 200 billion cells.  If we divide 200 / 1.2, we get 167ml; therefore, pitching anywhere between 150 and 175ml of settled, thick slurry will yield approximately an equal number of cells as a 1L starter at high krausen. Pitching less less slurry will yield more new cell growth in well-aerated wort while pitching more slurry will increase the average age of the cells in the culture due to suppressed new cell growth.  That is why overpitching is a poor practice in a serially re-pitched brewery.  It is better to improve brewery hygiene than overpitch to avoid contamination from wild microflora.  For most part, we do not base pitch rates based a fermentation reaching projected terminal gravity.  That is function of genetics and dissolved O2 demand.  We can seriously underpitch if there is enough dissolved O2 to support the number of replication cycles necessary to reach maximum cell density and our brewery hygiene is impeccable.  Suggested pitching rates are for commercial brewing, which accounts for the difficulty encountered in keeping a commercial brewery and brewing equipment spotless.  Pitching rates are primarily about outcompeting competitors.
Title: Re: Reusing 34/70 dry lager yeast
Post by: TXFlyGuy on November 18, 2020, 05:35:20 pm
You want to pitch around 150ml of settled, thick slurry per five gallons of wort, especially if you plan to serially repitch a culture.  Underpitching is okay.  Overpitching leads to insufficient new cell growth to sustain a culture over multiple repitches.

Hmmmmm...I pitch 475 ml, or 1 pint per 5 gallons. We always over pitch for lagers. With good results. Little or no lag time.
Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on November 18, 2020, 06:35:15 pm
You want to pitch around 150ml of settled, thick slurry per five gallons of wort, especially if you plan to serially repitch a culture.  Underpitching is okay.  Overpitching leads to insufficient new cell growth to sustain a culture over multiple repitches.

Hmmmmm...I pitch 475 ml, or 1 pint per 5 gallons. We always over pitch for lagers. With good results. Little or no lag time.

Lag time is a canard.
Title: Re: Reusing 34/70 dry lager yeast
Post by: majorvices on November 18, 2020, 08:00:40 pm
I find the yeast picthing calculators handy and convenient. Gives you an idea how much yeast you need for every batch. http://www.mrmalty.com/calc/calc.html

I have counted counted cells with a microscope and hemocytometer and matched it very closely with these results.

I have also counted stained yeast cells using an hemocytometer and a microscope. It is an interesting exercise and necessary for commercial brewing, but has limited use at home.  At this point, I really do not find yeast calculators to be all that useful.  I find rules of thumb combined with my experience with a culture to be more useful.  That being said, what it interesting is that Mr. Malty's standard re-pitch suggestion is 173ml, which is basically a 1L starter at maximum cell density. His ale pitching rate is 500ml at maximum cell density, which solidifies my assertion that underpitching by as much as 50% makes no difference in fermentation outcome while providing enough new cell growth that a culture can be serially re-pitched more than a couple of times without worrying about a huge loss in viability, that is, as long as one's wort is well aerated.   I have always re-pitched between 150 and 175ml of settled slurry per 5.25 gallons.  That is based in the rule of thumb that 1ml of settled, thick slurry contains approximately 1.2 billion cells as well as the accepted average maximum cell density of a 1L starter, which is 200 billion cells.  If we divide 200 / 1.2, we get 167ml; therefore, pitching anywhere between 150 and 175ml of settled, thick slurry will yield approximately an equal number of cells as a 1L starter at high krausen. Pitching less less slurry will yield more new cell growth in well-aerated wort while pitching more slurry will increase the average age of the cells in the culture due to suppressed new cell growth.  That is why overpitching is a poor practice in a serially re-pitched brewery.  It is better to improve brewery hygiene than overpitch to avoid contamination from wild microflora.  For most part, we do not base pitch rates based a fermentation reaching projected terminal gravity.  That is function of genetics and dissolved O2 demand.  We can seriously underpitch if there is enough dissolved O2 to support the number of replication cycles necessary to reach maximum cell density and our brewery hygiene is impeccable.  Suggested pitching rates are for commercial brewing, which accounts for the difficulty encountered in keeping a commercial brewery and brewing equipment spotless.  Pitching rates are primarily about outcompeting competitors.

My only point is that, for chronic underpitchers and new brewers, looking at how much yeast they actually should be pitching is helpful. And the yeast pitching calculators can give them an idea. I'm not sure why a lot of brewers seem to have moved on from recommending them especially when underpitching is a far bigger problem in homebrewing that overpitching.
Title: Reusing 34/70 dry lager yeast
Post by: BrewBama on November 18, 2020, 08:02:22 pm
Lag time is a canard.

We agree to disagree. I believe lag time is one of a few indications of health and viability.

I agree with this:

... the yeast pitching calculators can give them an idea. I'm not sure why a lot of brewers seem to have moved on from recommending them especially when underpitching is a far bigger problem in homebrewing that overpitching.

...and this:

“It is also important that the lag phase not last too long, ... Although most worts will remain stable for at least 24 h, it is best to err on the side of caution and aim for active fermentation within 15 h.” — Chris White from the The Oxford Companion to Beer definition of lag phase.

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Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 20, 2020, 06:15:40 am
Hmmmmm...I pitch 475 ml, or 1 pint per 5 gallons. We always over pitch for lagers. With good results. Little or no lag time.

And a progressively less variable culture with every repitch
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 20, 2020, 06:20:34 am
My only point is that, for chronic underpitchers and new brewers, looking at how much yeast they actually should be pitching is helpful. And the yeast pitching calculators can give them an idea. I'm not sure why a lot of brewers seem to have moved on from recommending them especially when underpitching is a far bigger problem in homebrewing that overpitching.

Underpitching was a serious problem when I first started to brew because commercial cultures were tiny compared to today.  The average White Labs culture doubles at most two times in a 1L starter.  I am finding that modern amateur brewers who repitch are overpitching, often seriously overpitching. Bragging about having little to no lag time demonstrates a fundamental lack of understanding about yeast culture management.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 20, 2020, 06:31:45 am
We agree to disagree. I believe lag time is one of a few indications of health and viability.

Well, I have to respectively disagree with you and agree with Denny.  There is a difference between a lag time of 15 hours and little to no lag time. Lag time is critical to yeast culture viability.  A lag time of over 24 hours is definitely a sign that one pitched too few viable cells.  One of the biggest problems in amateur brewing today is the overuse of attemperation.  I do not know where the dogma of pitching at a lower temperature than the fermentation temperature originated, but it is a recipe for long lag periods.  The optimal replication temperature for most brewing ale cultures is 30C/86F.  The replication period grows larger as we reduce temperature.  In my humble opinion, it is better to pitch a few degrees higher and allow the fermentation to come down to target fermentation than vice versa, but dogma almost always trumps science in amateur brewing.  The largest determiner of higher alcohol and ester production is not temperature.  It is wort composition, specifically carbon-to-nitrogen ratio.
Title: Re: Reusing 34/70 dry lager yeast
Post by: ynotbrusum on November 20, 2020, 11:12:29 am
A friend of mine who went to Siebel would pitch his lagers a bit warm and allow them to cool over the first 24-36 hours to fermentation range, going from 64F down to 52-54F.  He won many comps before going pro
Title: Reusing 34/70 dry lager yeast
Post by: BrewBama on November 20, 2020, 01:10:34 pm
We agree to disagree. I believe lag time is one of a few indications of health and viability.

...  There is a difference between a lag time of 15 hours and little to no lag time. Lag time is critical to yeast culture viability.  A lag time of over 24 hours is definitely a sign that one pitched too few viable cells.  ...

I may be confusing my terms. I agree with everything you said here. ...which is what I thought I said or at least intended.  I believe 12-18 hrs is about right.

I believe a cpl other indications of healthy and viable yeast pitched at the proper amount are the rate the fermentation is taking place and a complete finish — both based on expectations for the strain. 

Sluggish fermentation and lower than expected attenuation can be attributed to yeast pitch rate and health (among other things).

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Title: Re: Reusing 34/70 dry lager yeast
Post by: doc280 on November 20, 2020, 04:47:22 pm
I made my transfer from fermenter to keg and had two pints of yeast cake and beer mixture remaining in the fermenter. I just went with one pint of this mixture into my fresh batch, pitched at 59 F,  fermentation temp 56 F, it took off with in 12 hours.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Steve Ruch on November 20, 2020, 06:42:03 pm
A friend of mine who went to Siebel would pitch his lagers a bit warm and allow them to cool over the first 24-36 hours to fermentation range, going from 64F down to 52-54F.  He won many comps before going pro
I've had good results with a similar approach. I can only get my wort down to low-mid 60s so I pitch the yeast late afternoon and put the fv in a cabinet that's near 50. The wort gets down to the low 50s by morning and the yeast is working by noon or so.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 21, 2020, 09:33:56 pm
I've had good results with a similar approach. I can only get my wort down to low-mid 60s so I pitch the yeast late afternoon and put the fv in a cabinet that's near 50. The wort gets down to the low 50s by morning and the yeast is working by noon or so.

The practice of pitching a few degrees higher than fermentation and allowing the wort to come down in temperature works much better than the inverse.
Title: Re: Reusing 34/70 dry lager yeast
Post by: majorvices on November 22, 2020, 01:40:05 pm
I have had great success over the years pitching at or near pitching temps. If pitched slightly warmer and brought down before fermentation starts that's fine. Starting a fermentation off warm and bringing temp down is what makes me cringe.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 22, 2020, 02:59:41 pm
I have had great success over the years pitching at or near pitching temps. If pitched slightly warmer and brought down before fermentation starts that's fine. Starting a fermentation off warm and bringing temp down is what makes me cringe.

I agree if we are talking about more than five to ten degree difference combined with a slow reduction in temperature, which is probably more common without artificial cooling in warmer climates.  I have always pitched lagers around 16C (61F) and allowed them to drop into the 13C (55F) range.  I routinely pitch ales at 22C (72F) and allow them to cool to 18C (65F). I cannot remember when I fermented an ale below 65F (internal) on purpose.  That may have happened a couple of times during the early days when the temperature in my basement dropped below 17C (62F).  However, I used to brew with the seasons back in those days, so I usually switched over to making lager when ambient temperature in my basement dropped below 16C.   That basement would get down to as low as 9C during the dead of winter because almost half of the wall height was above grade.
Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on November 22, 2020, 03:16:25 pm
I've had good results with a similar approach. I can only get my wort down to low-mid 60s so I pitch the yeast late afternoon and put the fv in a cabinet that's near 50. The wort gets down to the low 50s by morning and the yeast is working by noon or so.

The practice of pitching a few degrees higher than fermentation and allowing the wort to come down in temperature works much better than the inverse.

Maybe in theory. I don't doubt you.  But my experience is that I get better results the other way around .
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 22, 2020, 04:46:33 pm
Maybe in theory. I don't doubt you.  But my experience is that I get better results the other way around .

I have not found a single reference to pitching below fermentation temperature outside of the amateur brewing forums.  Most professional references I have seen state to pitch at fermentation temperature or a few degrees higher.  Heck, Chris White take things to the extreme by stating that a lager fermentation can be started in the in high 60s F.   

https://www.whitelabs.com/faq/brewing/what-temperature-should-i-pitch-lager-yeast


I have never started a lager above 18C, but I think I am going to try it when manage to get my new brew house up and running.  I prefer to pitch as soon as possible, which means as soon as I can get the wort down to as far as my wort chiller can get it given my water supply temperature.  I used to be able to get my wort down to the temperature of the chilling water with a gravity-fed 25' counterflow chiller.  It can be done with a pump-fed counterflow chiller, but the chiller has to be longer or the flow rate needs to be reduced to that of a gravity-fed counterflow chiller, which is not fast.

By the way, I moving completely away from using US customary units of measure, as they no longer make sense to me in the world of brewing.  I buy grain in kilograms, measure starter media in grams, and all of the yeast work I do is in metric.  Every brewing and brewing science publication I read uses the metric system. It is a shame that the U.S. is one of the few countries in the world that still holds on to an Imperial units of measure-based system when even Great Britain has moved away from it for the most part.  While I may be wrong, I believe that we are the only industrialized country in the world that has held on to the Fahrenheit scale.  I believe that I have mentioned it before, but the rest temperatures 140, 149, and 158F translate to 60, 65, and 70C.  It is a lot easier to remember 60, 65, and 70C.  The metric system makes more sense than U.S. customary units of measure after one stops thinking in U.S. units and converting to metric units and starts thinking in metric units. It is like a learning a new language in that way. Plus, it is a lot easier to share information with non-American brewers who are forced to do conversions to U.S. units.  What is interesting is that every school-age American kid in the seventies was taught the metric system.  Back then, it was the members of the greatest generation and the older members of the silent generation who were resistant to switching to the metric system.  Today, Americans still hold on to U.S. units even though the U.S., in practice, is a mixed U.S. units/metric units world, just look at tools.  I have to have U.S. and metric wrenches in order to work on the things I own.  I have to be aware of metric thread bolts and screws.  I just worked on gas line flare fittings that are 1/4", but the outside of the swivel nut is 14mm.
Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on November 22, 2020, 04:57:45 pm
Mark, I appreciate your info and advice,  but I live by the words "Reality often astonishes theory".  I learn the sciende and try it out.  Because I understand the science, I also try out things that may appear contrary to science.  Whichever gets me the results I want is what I do.  All that matters is the beer in the glass.
Title: Re: Reusing 34/70 dry lager yeast
Post by: hopfenundmalz on November 23, 2020, 10:58:10 pm
One of the best beers that I've ever poured down my neck was the PH from the classic cellar in Pilsen. The unfiltered unpasteurized one, straight from the 4000 Liter Lagering barrels.

That beer is pitched at 5C, then rises, how high I'm not sure. They had daily temperature reading marked in chalk on the wooden fermenters. Not sure of the final temp.

New phone, still figuring how to get old images to where tapatalk will find them.


Title: Re: Reusing 34/70 dry lager yeast
Post by: BrewBama on November 23, 2020, 11:33:58 pm
...  Whichever gets me the results I want is what I do.  All that matters is the beer in the glass.

I’ll drink to that.

The science is fascinating ...and Mark, you are a wealth of knowledge. I take copious notes when you post. Thank you for that.


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Title: Re: Reusing 34/70 dry lager yeast
Post by: Cliffs on November 24, 2020, 12:48:37 am
sometimes I think I know a bit about yeast, and then I read a saccharomyces post and am brought back down to earth :)
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 26, 2020, 07:21:44 pm
Mark, I appreciate your info and advice,  but I live by the words "Reality often astonishes theory".  I learn the sciende and try it out.  Because I understand the science, I also try out things that may appear contrary to science.  Whichever gets me the results I want is what I do.  All that matters is the beer in the glass.

I am not a pure scientist, but like most engineering types, I rely on science to put me on the page.  Engineering is applied mathematics combined with applied science.  It is a discipline that combines theory plus practice.  In that way, engineers are neither mathematicians or scientists. However, there no denying that theory is what allows engineers to push the outside of the envelope. That being said, most of what is encountered in day-to-day engineering is not outside of the envelope work.  It is step-wise refinement, which relies on empirical data because most of the models we have are merely approximations of real-world phenomena.  That mindset is the reason why I push knowing how a particular culture performs in one's brewery is cannot be replaced by a yeast calculator.   It is also why I do not pitch below fermentation temperature because I know that it extends the replication period.

I am curious as to why the brewery sited by Jeff pitches that low.  Is it because the practice improves fermentation or because it helps to control thermal runaway?  Metabolic activity is very high during replication.  Cooling a batch of wort enough to prevent thermal runaway is no big deal for an amateur brewer.  However, cooling 3500+ hectoliters of activity fermenting wort is an entirely different engineering problem.  One way to do that is to slow replication, which spreads heat production over a longer period.
Title: Re: Reusing 34/70 dry lager yeast
Post by: lupulus on November 26, 2020, 07:46:20 pm


Maybe in theory. I don't doubt you.  But my experience is that I get better results the other way around .

I have not found a single reference to pitching below fermentation temperature outside of the amateur brewing forums.  Most professional references I have seen state to pitch at fermentation temperature or a few degrees higher.

Narziss, Kunze, Back all recommend pitching below fermentation temperature.
Can you list the pro references you have seen?
Thanks!

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Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 26, 2020, 08:23:25 pm
Narziss, Kunze, Back all recommend pitching below fermentation temperature.
Can you list the pro references you have seen?

Most of the professional publications I have read do not call for pitching below fermentation temperature. I have never read a German brewing publication because a) I do not speak German and b) the books that have been translated to English are ridiculously priced.  Chris White is the big reference for pitching above fermentation temperature and allowing the temperature to drop.  I trust Chris because there is no doubt that he has put time in the woodshed with respect to this one and I understand yeast well enough to know that what he is doing is backed up by science.  Chris was the first person I heard talk about fermenting lagers under pressure at what are considered to be ale temperatures.  Most brewers would think that was blasphemy.  He and his team are routinely pushing the outside of the envelope.  One of the largest costs encountered in brewing is refrigeration.  That is why there is so much interest in the Kveik cultures.

Th reality is that lager brewing practices are sub-optimal for ale brewing.  Carlsberg Unterhefe No. 1 (the Saaz family type yeast strain) combined with mechanical refrigeration made brewing on scale that was previously impossible.  Why?  Because Saaz strains are highly cryotolerant and wild yeast and bacteria are not, which means a brewer can get away with practices that will not fly in an ale brewery because fermentation temperatures cannot be dropped low enough to avoid wild yeast and bacteria replication.  With ale brewing, one has to rely on the yeast culture consuming all of the dissolved O2, lowering the pH, and producing ethanol in order to out compete competitors.  With lager brewing, one can hold the temperature low enough that competitors are shut out from the start.  In essence, lager brewing is a completely different type of brewing where many of the rules do not apply to ale brewing and vice versa.
Title: Re: Reusing 34/70 dry lager yeast
Post by: hopfenundmalz on November 26, 2020, 08:27:16 pm
https://photos.app.goo.gl/2ZRssskacaYxsRj6A

Photos from Pilsner Urquell's cellars where they still make the unfiltered in pasteurized beer.

Photo of wood fermenter. Those have about 4000 liters. You can still see some krausen.

Second is the day in dd/mm as they do in Europe. Temp is next.

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Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 26, 2020, 08:32:32 pm
With a rise to 8C, that is definitely a Saaz lager strain.
Title: Re: Reusing 34/70 dry lager yeast
Post by: hopfenundmalz on November 26, 2020, 08:36:03 pm
With a rise to 8C, that is definitely a Saaz lager strain.

I had to look, the picture was taken on Sept 4. It could be done, or it could rise more.

If I ever get back I will ask more questions.  :D
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 26, 2020, 08:38:26 pm
One thing I would like to add that most brewers are not thinking about is delta-T between the starter and the wort into which the culture is being pitched.  Ideally, a culture should be close in temperature to the wort into which it is being pitched in order to avoid temperature shock.  Pitching a cooler starter into warmer wort is preferred to pitching a warmer starter into cooler wort.  Most starters are in the 20 to 22C range when pitched.
Title: Re: Reusing 34/70 dry lager yeast
Post by: TXFlyGuy on November 26, 2020, 10:49:25 pm
One of the best beers that I've ever poured down my neck was the PH from the classic cellar in Pilsen. The unfiltered unpasteurized one, straight from the 4000 Liter Lagering barrels.

That beer is pitched at 5C, then rises, how high I'm not sure. They had daily temperature reading marked in chalk on the wooden fermenters. Not sure of the final temp.

New phone, still figuring how to get old images to where tapatalk will find them.

Been there, done that! Best beer ever! The beer you see here is the actual beer served to visitors, made the original way.
(https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/005342726106/media/1684464647209497/medium/1606430738/enhance)
(https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/005342726106/media/1684464696689093/medium/1606430781/enhance)
(https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/005342726106/media/1665701038791320/medium/1606430799/enhance)
Title: Re: Reusing 34/70 dry lager yeast
Post by: lupulus on November 26, 2020, 11:56:59 pm
Narziss, Kunze, Back all recommend pitching below fermentation temperature.
Can you list the pro references you have seen?

Most of the professional publications I have read do not call for pitching below fermentation temperature. I have never read a German brewing publication because a) I do not speak German and b) the books that have been translated to English are ridiculously priced.  Chris White is the big reference for pitching above fermentation temperature and allowing the temperature to drop.  I trust Chris because there is no doubt that he has put time in the woodshed with respect to this one and I understand yeast well enough to know that what he is doing is backed up by science.  Chris was the first person I heard talk about fermenting lagers under pressure at what are considered to be ale temperatures.  Most brewers would think that was blasphemy.  He and his team are routinely pushing the outside of the envelope.  One of the largest costs encountered in brewing is refrigeration.  That is why there is so much interest in the Kveik cultures.

Th reality is that lager brewing practices are sub-optimal for ale brewing.  Carlsberg Unterhefe No. 1 (the Saaz family type yeast strain) combined with mechanical refrigeration made brewing on scale that was previously impossible.  Why?  Because Saaz strains are highly cryotolerant and wild yeast and bacteria are not, which means a brewer can get away with practices that will not fly in an ale brewery because fermentation temperatures cannot be dropped low enough to avoid wild yeast and bacteria replication.  With ale brewing, one has to rely on the yeast culture consuming all of the dissolved O2, lowering the pH, and producing ethanol in order to out compete competitors.  With lager brewing, one can hold the temperature low enough that competitors are shut out from the start.  In essence, lager brewing is a completely different type of brewing where many of the rules do not apply to ale brewing and vice versa.
A few disconnected comments.

Don't know of a pro publication with lager expertise that recommends this.
The yeast reference for lager brewers is G Annemüller.

Augustiner has been fermenting under pressure well before it was brought up in the US pro or homebrew forums.

My guess is that the combination of vitality and yeast volume that's required for correct lager brewing would make it too costly for a yeast company to sell the right volume pitch at a reasonable price, but I don't know.

Annemüller, Narziss and others have the volumes you are to pitch for a proper lager fermentation.

Prost!

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Title: Re: Reusing 34/70 dry lager yeast
Post by: Northern_Brewer on November 27, 2020, 12:15:21 pm
I have not found a single reference to pitching below fermentation temperature outside of the amateur brewing forums.  Most professional references I have seen state to pitch at fermentation temperature or a few degrees higher.

In British brewing it's historically always been the norm to pitch fairly cool and then let it free-rise - and since cooling became available, then to come down again a bit towards the end of fermentation to stop the bugs cleaning up too much.

But if you look at the British commercial recipes on Ron Pattinson's site (http://barclayperkins.blogspot.com), you'll see that almost all of them are pitching in the 59-63F range (including the Scottish ones, they're not pitching at near-lager temperatures as some conventional wisdom would make out).

Great Britain has moved away from it for the most part.  While I may be wrong, I believe that we are the only industrialized country in the world that has held on to the Fahrenheit scale.

Come on, you've something in common with Liberia there!

Whereas here in the UK (not just Great Britain), we drive at 50mph to a pub where we'll have a 50g pack of peanuts and a (20oz) pint of lager dispensed from a 50-litre keg and a pint of ale from a 9-gallon cask.

It's a mess - although to be fair miles and drink-pints are the only real exceptions to metric, and are protected in law. And temperatures near freezing are always in centigrade whilsts hot temperatures are expressed in a mix of centrigrade and Farenheit, particularly in newspaper headlines.

To be honest, the one that really confused me was the gallons/pints thing. I knew in theory that the US had its own gallons, but it took me a while to click that all these "5 gallon" homebrew recipes were actually using 19 litres rather than 23 litres.

And grams/litre for hops and grist is just so, so much easier to scale...
Title: Re: Reusing 34/70 dry lager yeast
Post by: TXFlyGuy on November 27, 2020, 01:26:51 pm
With regards to scales involving temperature, there is a reason we have kept the Fahrenheit scale. It is far finer, i.e., more accurate than Centigrade / Celsius.
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.
We are all free to use the scale we prefer...at least for the time being.
Title: Re: Reusing 34/70 dry lager yeast
Post by: tommymorris on November 27, 2020, 01:50:06 pm
With regards to scales involving temperature, there is a reason we have kept the Fahrenheit scale. It is far finer, i.e., more accurate than Centigrade / Celsius.
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.
We are all free to use the scale we prefer...at least for the time being.
Re: precision. There is nothing stopping a person from using one or more digits to the right of the decimal point when measuring temperature in Celsius.
Title: Re: Reusing 34/70 dry lager yeast
Post by: hopfenundmalz on November 27, 2020, 02:29:42 pm
With regards to scales involving temperature, there is a reason we have kept the Fahrenheit scale. It is far finer, i.e., more accurate than Centigrade / Celsius.
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.
We are all free to use the scale we prefer...at least for the time being.
Re: precision. There is nothing stopping a person from using one or more digits to the right of the decimal point when measuring temperature in Celsius.

Correct. If I switch a digital thermometer from C to F, does it become more accurate? No.
Title: Re: Reusing 34/70 dry lager yeast
Post by: TXFlyGuy on November 27, 2020, 02:51:55 pm
With regards to scales involving temperature, there is a reason we have kept the Fahrenheit scale. It is far finer, i.e., more accurate than Centigrade / Celsius.
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.
We are all free to use the scale we prefer...at least for the time being.
Re: precision. There is nothing stopping a person from using one or more digits to the right of the decimal point when measuring temperature in Celsius.

You have helped my argument. Why use decimal points, when whole numbers are readily available?
Again...it's my personal hangup. For those who prefer C to F, with the required fractions, knock yourself out.
Title: Re: Reusing 34/70 dry lager yeast
Post by: TXFlyGuy on November 27, 2020, 02:55:06 pm
With regards to scales involving temperature, there is a reason we have kept the Fahrenheit scale. It is far finer, i.e., more accurate than Centigrade / Celsius.
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.
We are all free to use the scale we prefer...at least for the time being.
Re: precision. There is nothing stopping a person from using one or more digits to the right of the decimal point when measuring temperature in Celsius.

Correct. If I switch a digital thermometer from C to F, does it become more accurate? No.

My point is Fahrenheit is a finer scale, and most often does not require the use of fractions to accurately depict the correct temperature, unlike C.

This will help illustrate...I flew B-777's for a major US airline. Internationally, around the world. All of our performance data such as take off performance, climb performance, etc., was based on using Fahrenheit as it is a finer scale avoiding the need for fractions.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 27, 2020, 03:23:42 pm
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.

I do not know where you grew up, but I was taught the metric system in junior high school (what is referred to as middle school these days) in the seventies in preparation for the U.S. to move to it. However, the movement fizzled out (does anyone remember speed limit signs and speedometers in metric and U.S. customary units of measure).  The reality is that the U.S. has not been a pure U.S. customary units of measure country for the better part of five decades.  Legal alcohol has not been sold in U.S. customary units since 10/1/1976.  For example, the fifth was replaced with a volume of 750ml.  The quart was replaced with the liter. What is referred to as a pint today is actually 375ml (12.68 fl. ozs).  A half pint is 200ml (6.76 fl. ozs).   Non-alcoholic beverages are mixed U.S. customary units and the metric system.  Bottle sizes less than a liter are sold in ounces.  Bottle a liter and above are sold in liters.  Automobiles use a combination of U.S. customary units and metric. 

A lot of Americans refer to our system as imperial units of measure.  However, that is only partially correct.   A U.S. inch is equal to an imperial inch.  However, a U.S. fluid ounce is not equal to an imperial ounce.  A U.S. fluid ounce is 1.04084 imperial ounces.  What we refer to as a barrel of beer today actually started out as a wine unit of measure; namely, the Queen Anne barrel.  Our gallon size is actually the Queen Anne gallon, which is why it is different than the imperial gallon.  A Queen Anne barrel is 1/8th of a tun, which is 252 Queen Anne gallons. 

The reality is that U.S. customary units are an incoherent hodgepodge. The only reason Americans understand U.S. customary units is because they are raised with the system and most only know a fraction of it.  Weight and volume are disconnected, which is why most lab work is performed using the metric system.  The U.S. had the opportunity to be the second country to adopt the metric system and Thomas Jefferson passed because it was a French creation that he found to be too decimal (base 10), which is weird because he created the first base 10 currency in the world.  If want to talk about accuracy, the metric system blows U.S. customary units of measure out of the water precisely because it is base 10.  For example, what base is U.S. liquid volume?  A quick look at the units of measure for a sub-fluid ounce will demonstrate how much of a mess our system is with respect to metric system.  A dram is 1/8th of a fluid ounce. Really?  That makes absolutely no sense once one realizes that most Americans are only taught base 10 arithmetic. Few people outside of computer scientists, computer engineers, mathematicians, and other select engineering types can work in any numerical base other than 10.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 27, 2020, 03:51:51 pm
In British brewing it's historically always been the norm to pitch fairly cool and then let it free-rise - and since cooling became available, then to come down again a bit towards the end of fermentation to stop the bugs cleaning up too much.

But if you look at the British commercial recipes on Ron Pattinson's site (http://barclayperkins.blogspot.com), you'll see that almost all of them are pitching in the 59-63F range (including the Scottish ones, they're not pitching at near-lager temperatures as some conventional wisdom would make out).

Bingo!  Most of the ale strains that Americans use originally came from the UK where they were selected under pressure over hundreds of years sans refrigeration.  If the mixed cultures from which modern ale strains of British were isolated did not perform well at between 18 and 22C, they would have been discarded.  Lager brewing is a completely different kind of brewing with its own set of rules.  Lager cultures were not originally cropped from the top.  The practice of top-cropping is what allowed ale brewers to separate domesticated yeast from wild yeast and bacteria because wild yeast and bacteria do not floc to the top.

Quote
Great Britain has moved away from it for the most part.  While I may be wrong, I believe that we are the only industrialized country in the world that has held on to the Fahrenheit scale.

Come on, you've something in common with Liberia there!

Lol! There are few Caribbean islands that also use it.
 
Quote
Whereas here in the UK (not just Great Britain), we drive at 50mph to a pub where we'll have a 50g pack of peanuts and a (20oz) pint of lager dispensed from a 50-litre keg and a pint of ale from a 9-gallon cask.

It's a mess - although to be fair miles and drink-pints are the only real exceptions to metric, and are protected in law. And temperatures near freezing are always in centigrade whilsts hot temperatures are expressed in a mix of centrigrade and Farenheit, particularly in newspaper headlines.

To be honest, the one that really confused me was the gallons/pints thing. I knew in theory that the US had its own gallons, but it took me a while to click that all these "5 gallon" homebrew recipes were actually using 19 litres rather than 23 litres.

And grams/litre for hops and grist is just so, so much easier to scale...

However, at least the UK is making an effort to bring your units of measure in line with the rest of the world.  That is a big deal for older members of British society who were brought up on the imperial system.  Americans are too obstinate to adopt the metric system wholeheartedly.  However, then again America as a very high percentage of marginally educated people compared to the rest of the industrialized world.  Over thirty million adult Americans cannot read.  We all know that being able to read is important to learning.  The number one gift a teacher can give to a child is to teach him/her how to read.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 27, 2020, 04:22:25 pm
Don't know of a pro publication with lager expertise that recommends this.
The yeast reference for lager brewers is G Annemüller.

The keyword here is "lager."  Lager and ale fermentation practices are very different.

Quote
My guess is that the combination of vitality and yeast volume that's required for correct lager brewing would make it too costly for a yeast company to sell the right volume pitch at a reasonable price, but I don't know.

Annemüller, Narziss and others have the volumes you are to pitch for a proper lager fermentation.

Now, you should ask yourself why these large pitch rates are required.  Is it because the starting temperature is so low that it retards replication to the point where new cell growth is seriously hampered?  Pitching a large volume of yeast also limits the number of times a culture can be repitched because of the lack of new cell growth during fermentation.

By the way, there is a lot of modern research that renders much of German brewing to the classification of dogma rather than science.  Only Saaz lager strains are adapted well to very cold fermentation because they are allotriploids composed two sets Saccharomyces eubayanus (S. eubayanus) chromosomes and one set of Saccharomyces cerevisiae (S. cerevisiae).  Frohberg strains are not as cryotolerant because they are allotetraploids composed of two sets of S. eubayanus chromosomes and two sets of S. cerevisiae chromosomes with much of the cryotolerance inherited from S. eubayanus deleted.  W-34/70 is the Frohberg type strain (it is orignally from the Frohberg brewery in Grima, Saxony).  That is why W-34/70 performs astonishingly well at what are considered to be low ale fermentation temperatures.  Below is a link to a publication by the former head of yeast genetics at Carlsberg Laboratories (the place when the first Saaz strain, Carlsberg Unterhefe No. 1, was isolated in 1883 by Emil Hansen). Carlsberg Laboratories is also where the field of yeast genetics was founded by Ojvind Winge and Catherine Roberts.  I exchanged e-mail with Jürgen Wendland a few years ago when I was researching the origins of an old Danish ale yeast culture deposited in a culture collection by Catherine Roberts.  He appears to be cool guy.
 
https://ec.asm.org/content/13/10/1256
Title: Re: Reusing 34/70 dry lager yeast
Post by: TXFlyGuy on November 27, 2020, 04:58:10 pm
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.

I do not know where you grew up, but I was taught the metric system in junior high school (what is referred to as middle school these days) in the seventies in preparation for the U.S. to move to it. However, the movement fizzled out (does anyone remember speed limit signs and speedometers in metric and U.S. customary units of measure).  The reality is that the U.S. has not been a pure U.S. customary units of measure country for the better part of five decades.  Legal alcohol has not been sold in U.S. customary units since 10/1/1976.  For example, the fifth was replaced with a volume of 750ml.  The quart was replaced with the liter. What is referred to as a pint today is actually 375ml (12.68 fl. ozs).  A half pint is 200ml (6.76 fl. ozs).   Non-alcoholic beverages are mixed U.S. customary units and the metric system.  Bottle sizes less than a liter are sold in ounces.  Bottle a liter and above are sold in liters.  Automobiles use a combination of U.S. customary units and metric. 

A lot of Americans refer to our system as imperial units of measure.  However, that is only partially correct.   A U.S. inch is equal to an imperial inch.  However, a U.S. fluid ounce is not equal to an imperial ounce.  A U.S. fluid ounce is 1.04084 imperial ounces.  What we refer to as a barrel of beer today actually started out as a wine unit of measure; namely, the Queen Anne barrel.  Our gallon size is actually the Queen Anne gallon, which is why it is different than the imperial gallon.  A Queen Anne barrel is 1/8th of a tun, which is 252 Queen Anne gallons. 

The reality is that U.S. customary units are an incoherent hodgepodge. The only reason Americans understand U.S. customary units is because they are raised with the system and most only know a fraction of it.  Weight and volume are disconnected, which is why most lab work is performed using the metric system.  The U.S. had the opportunity to be the second country to adopt the metric system and Thomas Jefferson passed because it was a French creation that he found to be too decimal (base 10), which is weird because he created the first base 10 currency in the world.  If want to talk about accuracy, the metric system blows U.S. customary units of measure out of the water precisely because it is base 10.  For example, what base is U.S. liquid volume?  A quick look at the units of measure for a sub-fluid ounce will demonstrate how much of a mess our system is with respect to metric system.  A dram is 1/8th of a fluid ounce. Really?  That makes absolutely no sense once one realizes that most Americans are only taught base 10 arithmetic. Few people outside of computer scientists, computer engineers, mathematicians, and other select engineering types can work in any numerical base other than 10.

To answer your question, the great state of Iowa. North Central Iowa. Fort Dodge, which was an actual US Cavalry Fort.
We were not taught the metric system. But I did take three years of Spanish.
Again, I fully admit it's my personal problem. My brain is wired in "F".
Title: Re: Reusing 34/70 dry lager yeast
Post by: majorvices on November 27, 2020, 05:18:38 pm
Just to back track a little about professional literature and suggested pitching temp here is an excerpt from the MBAA Practical handbook For The Specialty Brewer Vol. 2

"(ale) pitching temperature is typically 59°-62°F (15°-17°C), climbing to 67°-70°F (20°-22°C)..."

... and for lager

"Wort is cooled to 45°F (7°C), aerated to a DO content of 8 ppm, and pitched... as the beer ferments, the temperature rises"
Title: Re: Reusing 34/70 dry lager yeast
Post by: lupulus on November 27, 2020, 06:35:31 pm
Re "there is a lot of modern research that renders much of German brewing to the classification of dogma rather than science."

Just for casual readers that happen to read this statement, I wish to state that it's not true at all.

The books, articles and dissertations are widely available.

Prost!

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Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 27, 2020, 06:58:29 pm
Just to back track a little about professional literature and suggested pitching temp here is an excerpt from the MBAA Practical handbook For The Specialty Brewer Vol. 2

"(ale) pitching temperature is typically 59°-62°F (15°-17°C), climbing to 67°-70°F (20°-22°C)..."

That is still not lager temperature.  It is just merely cool ale temperature.  The question to ask here is why?  What is gained?  I know what is lost.  The optimal replication temperature for Saccharomyces cerevisiae is 30C.  At 30C, the average replication period is 90 minutes. Every degree below 30C extends the replication period.   

Quote
... and for lager

"Wort is cooled to 45°F (7°C), aerated to a DO content of 8 ppm, and pitched... as the beer ferments, the temperature rises"

First off, fermentation temperature only rises if it is allowed to rise, which applies to both lager and ale fermentation. Are these practices from the days when fermentation temperature could not be precisely controlled; thereby, helping to prevent thermal overshoot?  Secondly, there are two different families of lager yeast with different optimum fermentation temperatures; therefore, this practice is based more on brewing dogma than science, especially in light of recent findings with respect to yeast genetics.   If one reads the publication I linked in my last post, one will see that only the Saaz family of lager strains exhibits significant cryotolerance.  In the case of Saaz strains optimum temperature is 10C/50F whereas optimum temperature for Frohberg strains is 22C/72F, which is at the higher end of normal ale temperatures.  Can we lower the temperature to retard fermentation to reduce growth-related metabolites? Absolutely! However growth-related metabolites are dependent on things other than temperature.  Attributes such as protein content and dissolved O2 enter the picture because higher alcohol production is the result of catabolism of amino acids (the building blocks of protein) via the Erhlich pathway and O2 has an effect of acetic acid production.  That means that treating higher alcohol and ester production as only a fermentation temperature-related problem is akin to treating the symptoms instead of fixing the problem. The carbon to nitrogen ratio of the wort as well as the amount of dissolved O2 have a major impact on higher alcohol and acetic acid production. In essence, high FAN coupled with low O2 is recipe for hot tasting, estery beers.  Fermenting at lower temperature to control higher alcohol and ester production is akin to putting a band-aid on a sucking chest wound.  If anyone wants to test this phenomenon, formulate two non-excessively hopped beers at a gravity of 1.060 (i.e., the malt and hops need to be in balance).  The first beer should be all malt.  The second beer should contain 20 to 30% flaked maize.  The all-malt beer is splash aerated.  The adjunct beer is venturi or direct O2 injection aerated.  One will have to adjust the hopping rate down on the adjunct beer to accommodate for its lighter body.  Both beers should be pitched with the same culture at the normal fermentation temperature for the given yeast culture.  The goal here is not to produce two identical beers.  It is to compare higher alcohol (hot flavors) and ester production between two different carbon to nitrogen ratios coupled with two different dissolved O2 levels.

From https://ec.asm.org/content/13/10/1256:

Quote
Lager yeast strains can be divided into two groups, Saaz/Carlsberg and Frohberg. This division is based on the geographic heritage of the strains and was supported by molecular analyses of transposition distribution in these strains (24). Only recently, the differences in fermentation performance of these two groups were analyzed. It was shown that group I/Saaz yeasts are better adapted to low-temperature growth conditions (10°C), while group II/Frohberg yeasts ferment better at a higher temperature (22°C). Differences in sugar utilization became apparent, as group II yeasts utilize maltotriose and group I yeasts do not. Additionally, flavor differences were identified showing that Saaz strains produce several fold-lower levels of, e.g., isoamyl acetate (banana flavor) than Frohberg strains (25, 26).

What is interesting is that Saaz strains do not ferment maltotriose.  They are also bigger producers of isoamyl acetate.

The MBAA recommendation is more than likely based on the fact that the American lager brewing industry was made possible by Emil Hansen generously sharing Carlsberg Unterhefe No. 1 (a.k.a. Sacchormyces Carlsbergensis) and the Carlsberg flask for pure culture propagation.  The Midwestern brewing industry was built on Carlsberg Unterhefe No. 1, which lives on today as Miller's lager strain (a.k.a. Wyeast 2042 Danish Lager).  Carlsberg Unterhefe No. 1 is the type strain for the Saaz family.
 
Title: Re: Reusing 34/70 dry lager yeast
Post by: hopfenundmalz on November 27, 2020, 07:04:10 pm
With regards to scales involving temperature, there is a reason we have kept the Fahrenheit scale. It is far finer, i.e., more accurate than Centigrade / Celsius.
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.
We are all free to use the scale we prefer...at least for the time being.
Re: precision. There is nothing stopping a person from using one or more digits to the right of the decimal point when measuring temperature in Celsius.

Correct. If I switch a digital thermometer from C to F, does it become more accurate? No.

My point is Fahrenheit is a finer scale, and most often does not require the use of fractions to accurately depict the correct temperature, unlike C.

This will help illustrate...I flew B-777's for a major US airline. Internationally, around the world. All of our performance data such as take off performance, climb performance, etc., was based on using Fahrenheit as it is a finer scale avoiding the need for fractions.

That means your pressure reading were in KPA? A tire example, 32 PSI=220.6 kPA, so a finer scale.

I used SI (metric) units at work. Got used to many and could go back and forth. Never got intuitive with pressure.

If you flew an Airbus would it be in degrees C? I'm honestly curious.

Edit.
A little Google time answered my question. Aviation uses USCS units due to the Weight Brothers, and how the US had influence after WWII. Airbus probably uses USCS in the cockpit.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 27, 2020, 07:31:23 pm
Re "there is a lot of modern research that renders much of German brewing to the classification of dogma rather than science."

Just for casual readers that happen to read this statement, I wish to state that it's not true at all.

The books, articles and dissertations are widely available.

Prost!

Sent from my SM-G960U using Tapatalk

The problem here is that a sizable percentage of German publications are only available in German.  The paper I linked was written by a recognized authority on lager yeast genetics who just happens to be German by birth.  His work on lager yeast genetics is being used by other scientists to push the outside of the evenlope.  Pretty much everything I post here is backed by peer-reviewed science, which I routinely check to see if it no longer holds. I am never going to rely on dogma, as dogma defines a way, not the only way to achieve a result.  Plus, dogma limits one's horizons.

Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 27, 2020, 07:38:35 pm
I used SI (metric) units at work. Got used to many and could go back and forth. Never got intuitive with pressure.

Engineers in the automotive industry had no choice, but to become fluent in SI units because the automotive was an early adopter of the metric system.  America will eventually adopt the metric system or risk being isolated from the world.  We are already a mixed country when it comes to units of measure.
Title: Re: Reusing 34/70 dry lager yeast
Post by: lupulus on November 27, 2020, 08:01:49 pm
Re "there is a lot of modern research that renders much of German brewing to the classification of dogma rather than science."

Just for casual readers that happen to read this statement, I wish to state that it's not true at all.

The books, articles and dissertations are widely available.

Prost!

Sent from my SM-G960U using Tapatalk

The problem here is that a sizable percentage of German publications are only available in German.  The paper I linked was written by a recognized authority on lager yeast genetics who just happens to be German by birth.  His work on lager yeast genetics is being used by other scientists to push the outside of the evenlope.  Pretty much everything I post here is backed by peer-reviewed science, which I routinely check to see if it no longer holds. I am never going to rely on dogma, as dogma defines a way, not the only way to achieve a result.  Plus, dogma limits one's horizons.
Contrary to a few incorrect comments in homebrew forums, there's zero dogma in german brewing.
Thermal load on boiling, low oxygen mashing, endosperm mashing, pressure fermentation have been incorporated to large scale brewing by germans. German brewing technology dominates brewing equipment world wide. There's no dogma there.

Sent from my SM-G960U using Tapatalk

Title: Re: Reusing 34/70 dry lager yeast
Post by: hopfenundmalz on November 27, 2020, 08:03:07 pm
All of us (in the USA) grew up with F. It is my standard temp of reference. All pitching temps with regards to W-34/70, and fermentation are referenced in F.

I do not know where you grew up, but I was taught the metric system in junior high school (what is referred to as middle school these days) in the seventies in preparation for the U.S. to move to it. However, the movement fizzled out (does anyone remember speed limit signs and speedometers in metric and U.S. customary units of measure).  The reality is that the U.S. has not been a pure U.S. customary units of measure country for the better part of five decades.  Legal alcohol has not been sold in U.S. customary units since 10/1/1976.  For example, the fifth was replaced with a volume of 750ml.  The quart was replaced with the liter. What is referred to as a pint today is actually 375ml (12.68 fl. ozs).  A half pint is 200ml (6.76 fl. ozs).   Non-alcoholic beverages are mixed U.S. customary units and the metric system.  Bottle sizes less than a liter are sold in ounces.  Bottle a liter and above are sold in liters.  Automobiles use a combination of U.S. customary units and metric. 

A lot of Americans refer to our system as imperial units of measure.  However, that is only partially correct.   A U.S. inch is equal to an imperial inch.  However, a U.S. fluid ounce is not equal to an imperial ounce.  A U.S. fluid ounce is 1.04084 imperial ounces.  What we refer to as a barrel of beer today actually started out as a wine unit of measure; namely, the Queen Anne barrel.  Our gallon size is actually the Queen Anne gallon, which is why it is different than the imperial gallon.  A Queen Anne barrel is 1/8th of a tun, which is 252 Queen Anne gallons. 

The reality is that U.S. customary units are an incoherent hodgepodge. The only reason Americans understand U.S. customary units is because they are raised with the system and most only know a fraction of it.  Weight and volume are disconnected, which is why most lab work is performed using the metric system.  The U.S. had the opportunity to be the second country to adopt the metric system and Thomas Jefferson passed because it was a French creation that he found to be too decimal (base 10), which is weird because he created the first base 10 currency in the world.  If want to talk about accuracy, the metric system blows U.S. customary units of measure out of the water precisely because it is base 10.  For example, what base is U.S. liquid volume?  A quick look at the units of measure for a sub-fluid ounce will demonstrate how much of a mess our system is with respect to metric system.  A dram is 1/8th of a fluid ounce. Really?  That makes absolutely no sense once one realizes that most Americans are only taught base 10 arithmetic. Few people outside of computer scientists, computer engineers, mathematicians, and other select engineering types can work in any numerical base other than 10.

Vehicles are engineered in metric now. The instrument panel on my vehicle can be changed to metric by selection in a menu. That was nice crossing into Canada on the way to the Portland homebrewcon to visit friends there.

Vestiges of US units still remain. Wheel size is in inches, while the tires are specified in metric.

One VP said at a presentation that there are universal constants such as, the speed of light, Avogadros number, and the bore spacing of a Chevy Small block V-8 (4.40 inches). Change the bore space and much of the production line would be scrapped.

Newer engines have metric bore spacing, bores to and so on.
Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on November 27, 2020, 08:16:20 pm
Re "there is a lot of modern research that renders much of German brewing to the classification of dogma rather than science."

Just for casual readers that happen to read this statement, I wish to state that it's not true at all.

The books, articles and dissertations are widely available.

Prost!

Sent from my SM-G960U using Tapatalk

The problem here is that a sizable percentage of German publications are only available in German.  The paper I linked was written by a recognized authority on lager yeast genetics who just happens to be German by birth.  His work on lager yeast genetics is being used by other scientists to push the outside of the evenlope.  Pretty much everything I post here is backed by peer-reviewed science, which I routinely check to see if it no longer holds. I am never going to rely on dogma, as dogma defines a way, not the only way to achieve a result.  Plus, dogma limits one's horizons.
Contrary to a few incorrect comments in homebrew forums, there's zero dogma in german brewing.
Thermal load on boiling, low oxygen mashing, endosperm mashing, pressure fermentation have been incorporated to large scale brewing by germans. German brewing technology dominates brewing equipment world wide. There's no dogma there.

Sent from my SM-G960U using Tapatalk

It may be scientific dogma, but it's still dogma.
Title: Re: Reusing 34/70 dry lager yeast
Post by: beerphilmcd on November 28, 2020, 12:17:14 am
I’ve run into problems with mangrove jack yeast producing terrible amounts of phenolic when repitched. For instance liberty bell is beautiful on the first pitch but turned my time tested blonde ale into a Belgian.

I learned this because I’ve repitched other yeast, dry and liquid, multiple times with nothing but positive results! I’ve ran Nottingham through 7 repitches and have  only had good repeatable results.


Sent from my iPhone using Tapatalk
Title: Re: Reusing 34/70 dry lager yeast
Post by: Northern_Brewer on November 28, 2020, 08:17:12 pm
In British brewing it's historically always been the norm to pitch fairly cool and then let it free-rise - and since cooling became available, then to come down again a bit towards the end of fermentation to stop the bugs cleaning up too much.

But if you look at the British commercial recipes on Ron Pattinson's site (http://barclayperkins.blogspot.com), you'll see that almost all of them are pitching in the 59-63F range (including the Scottish ones, they're not pitching at near-lager temperatures as some conventional wisdom would make out).

Bingo!  Most of the ale strains that Americans use originally came from the UK where they were selected under pressure over hundreds of years sans fermentation.  If the mixed cultures from which modern ale strains of British were isolated did not perform well at between 18 and 22C, they would have been discarded.  Lager brewing is a completely different kind of brewing with its own set of rules.  Lager ale cultures were not originally cropped from the top.  The practice of top-cropping is what allowed ale brewers to separate domesticated yeast from wild yeast and bacteria because wild yeast and bacteria do not floc to the top.

Except we weren't talking about top-cropping and lager versus ale, you made the general comment :
I have not found a single reference to pitching below fermentation temperature outside of the amateur brewing forums.  Most professional references I have seen state to pitch at fermentation temperature or a few degrees higher.



However, at least the UK is making an effort to bring your units of measure in line with the rest of the world.

Meh - not really, it was a big deal thirty+ years ago but there's not been a huge effort since we settled on the current system of exempting miles and beer-pints, but metric for everything else, which seems pretty stable. It's only an issue for the boomers who have now pretty much left the workplace, so it only crops up in minor things like "Brexit will allow us to buy carrots by the pound and no longer by the kg".

The Midwestern brewing industry was built on Carlsberg Unterhefe No. 1, which lives on today as Miller's lager strain (a.k.a. Wyeast 2042 Danish Lager). 

Except that 2042 is a Frohberg according to Langdon et al's lager sequencing paper (https://www.nature.com/articles/s41559-019-0998-8#Sec22) last year (see Supplementary Dataset 1) - in fact they reckon all mainstream homebrew yeasts are Frohberg.

You have helped my argument. Why use decimal points, when whole numbers are readily available?
Again...it's my personal hangup. For those who prefer C to F, with the required fractions, knock yourself out.

Why use a 100's column, when you can go all the way up to boiling point of water without it? And how many times do you need the extra precision of whole-number Farenheit, but are not in a position to record or measure centigrade? It's not like say the difference between an inch and a cm, where ordinary people have a good feel for quite small differences in length, people are not good on small differences in temperature. For most purposes centigrade has appropriate resolution.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 28, 2020, 09:26:22 pm
Except that 2042 is a Frohberg according to Langdon et al's lager sequencing paper (https://www.nature.com/articles/s41559-019-0998-8#Sec22) last year (see Supplementary Dataset 1) - in fact they reckon all mainstream homebrew yeasts are Frohberg.

That is interesting because Wyeast 2042 has always been referred to as Miller's strain and Miller was one of the Midwestern brewers who employed Carlsberg Unterhefe No. I and the Carlsberg flask. I hate to tell you, but Langdon's data is suspect. It could just be a reporting error, but W-34/70 is the Frohberg type strain (it is originally from the Frohberg brewery in Grimma, Saxony); however, it is listed as a Saaz strain on Langdon's spreadsheet. Jürgen Wendland and his team at Carlsberg Laboratories took W-34/70 apart genetically as few years ago.  If any institution is familiar with Saaz strains, it is Carlsberg Laboratories because CBS 1503, CBS 1513, and CBS 1538 are all Saaz strains that were isolated by Emil Hansen.  CBS 1513 is Carlsberg Unterhefe No. I and CBS 1503 is Carlsberg Unterhefe No. II.

From https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4187645/:

Quote
Lager yeast strains can be divided into two groups, Saaz/Carlsberg and Frohberg. This division is based on the geographic heritage of the strains and was supported by molecular analyses of transpositon distribution in these strains (24). Only recently, the differences in fermentation performance of these two groups were analyzed. It was shown that group I/Saaz yeasts are better adapted to low-temperature growth conditions (10°C), while group II/Frohberg yeasts ferment better at a higher temperature (22°C). Differences in sugar utilization became apparent, as group II yeasts utilize maltotriose and group I yeasts do not. Additionally, flavor differences were identified showing that Saaz strains produce severalfold-lower levels of, e.g., isoamyl acetate (banana flavor) than Frohberg strains (25, 26).

Ploidy determination of hybrid lager yeast strains has been a long-standing issue. Some advances came from a study using array-CGH and DNA sequence analysis covering several lager yeast strains (reference 12 and references therein). A 1n ploidy difference between group I and group II lager yeasts was identified. However, according to this study, group I yeasts appeared to be 2n and group II yeasts appeared to be 3n. Aneuploidy of lager yeasts and regions with copy number variations were also detected in another study using microarray hybridization (27), but only recently was it shown that, based on next-generation sequence and flow cytometry data, Saccharomyces carlsbergensis (group I) is essentially triploid, whereas the Weihenstephan 34/70 strain (group II) is (allo)tetraploid (26). Other studies were based on copy number variations in different strains, which also provided an estimate of the allotetraploid nature of group II lager yeasts (8).

If you noticed, Frohberg lager strains are not as cryotolerant as Saaz strains.  That is why W-34/70 is so forgiving at fermentation temperatures that we normally associate with lager brewing.  The fact that Frohberg strains can ferment maltotriose and Saaz strains cannot is probably the easiest test to check if a lager strain is Frohberg or Saaz just like the presence of absence of melibiose in a beer is a way to test if it is an ale or a lager.


With that said, a lot of Wyeast data is either wrong or we are associating the wrong source cultures with the Wyeast cultures.  For example, here is a description for Wyeast 2124, which most brewers assume is W-34/70.  However, if that is true, then the data below from Wyeast's website is wrong.

Quote
STRAIN: 2124
Bohemian Lager

Species: Saccharomyces pastorianus

Profile: This Carlsberg type yeast is the most widely used lager strain in the world. This strain produces a distinct malty profile with some ester character and a crisp finish. A versatile strain, that is great to use with lagers or Pilsners for fermentations in the 45-55°F (8-12°C) range. It may also be used for Common beer production with fermentations at 65-68°F (18-20°C). A thorough diacetyl rest is recommended after fermentation is complete.

Metric Temperature Range: 8-22 °C
This Carlsberg type yeast is the most widely used lager strain in the world. This strain produces a distinct malty profile with some ester character and a crisp finish. A versatile strain, that is great to use with lagers or Pilsners for fermentations in the 45-55°F (8-12°C) range. It may also be used for Common beer production with fermentations at 65-68°F (18-20°C). A thorough diacetyl rest is recommended after fermentation is complete.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 28, 2020, 09:46:33 pm
It may be scientific dogma, but it's still dogma.

I am assuming the lupulus is German.  The German population, as a whole, is very dogmatic.  They have rules and laws that would drive the average American crazy.  The German law/rule that blew my mind is known as "Abgeschlossene Ausbildung."   What it means is that one cannot just change careers.  One has to go through a formal program of study to change careers.  I learned about it because I used to hang out on a lutherie forum.  A really talented German luthier could not call himself a luthier in Germany because he was self-taught.  PRS Guitars would have never gotten off of the ground if the U.S. had a similar career-limiting law.

Here is Webster's definition of Dogma:

1a : something held as an established opinion especially : a definite authoritative tenet

b : a code of such tenets pedagogical dogma

c : a point of view or tenet put forth as authoritative without adequate grounds

2 : a doctrine or body of doctrines concerning faith or morals formally stated and authoritatively proclaimed by a church

Title: Re: Reusing 34/70 dry lager yeast
Post by: denny on November 28, 2020, 09:48:47 pm
It may be scientific dogma, but it's still dogma.

I am assuming the lupulus is German.  The German population, as a whole, is very dogmatic.  They have rules and laws that would drive the average American crazy.  The German law/rule that blew my mind is known as "Abgeschlossene Ausbildung."   What it means is that one cannot just change careers.  One has to go through a formal program of study to change careers.  I learned about it because I used to hang out on a lutherie forum.  A really talented German luthier could not call himself a luthier in Germany because he was self-taught.  PRS Guitars would have never gotten off of the ground if the U.S. had a similar career-limiting law.

Here is Webster's definition of Dogma:

1a : something held as an established opinion especially : a definite authoritative tenet

b : a code of such tenets pedagogical dogma

c : a point of view or tenet put forth as authoritative without adequate grounds

2 : a doctrine or body of doctrines concerning faith or morals formally stated and authoritatively proclaimed by a church

No, I don't think he is.
Title: Re: Reusing 34/70 dry lager yeast
Post by: hopfenundmalz on November 28, 2020, 11:12:19 pm
It may be scientific dogma, but it's still dogma.

I am assuming the lupulus is German.  The German population, as a whole, is very dogmatic.  They have rules and laws that would drive the average American crazy.  The German law/rule that blew my mind is known as "Abgeschlossene Ausbildung."   What it means is that one cannot just change careers.  One has to go through a formal program of study to change careers.  I learned about it because I used to hang out on a lutherie forum.  A really talented German luthier could not call himself a luthier in Germany because he was self-taught.  PRS Guitars would have never gotten off of the ground if the U.S. had a similar career-limiting law.

Here is Webster's definition of Dogma:

1a : something held as an established opinion especially : a definite authoritative tenet

b : a code of such tenets pedagogical dogma

c : a point of view or tenet put forth as authoritative without adequate grounds

2 : a doctrine or body of doctrines concerning faith or morals formally stated and authoritatively proclaimed by a church

No, I don't think he is.

He is not German, but knows a fair amount about German brewing.
Title: Re: Reusing 34/70 dry lager yeast
Post by: Saccharomyces on November 28, 2020, 11:15:34 pm
It appears that the Kunze text was first published in 1961 and it appears that texts written by Narziss are not quite as old, but are all old in terms of brewing science.  All of these texts were written before genetic sequencing, which means that anything related to yeast is based on outdated scientific information.  I am not attempting to take anything away from these brewing scientists.  They were accomplished in their day, but brewing science is not static.  To treat what they wrote as gospel in light of what has been learned in just the last ten years is, in fact, dogmatic.  The methods that they developed were based on the science of the day.
Title: Re: Reusing 34/70 dry lager yeast
Post by: lupulus on November 29, 2020, 12:00:50 am
The German law/rule that blew my mind is known as "Abgeschlossene Ausbildung."   What it means is that one cannot just change careers.  One has to go through a formal program of study to change careers.  I learned about it because I used to hang out on a lutherie forum.  A really talented German luthier could not call himself a luthier in Germany because he was self-taught.  PRS Guitars would have never gotten off of the ground if the U.S. had a similar career-limiting law.

Something to consider (not a defense of the system):
Education is almost free in Germany. Changing careers is a cost for those who don't go to College. It's an efficient system.
Won't get into the history, but nowadays the Ausbildung system is a buffer against uncontrolled immigration. A citizen of any EU country can work in Germany, but they need to learn German and do the Ausbildung, limiting the number of non-college immigrants.
Taxes are very low if you compare the perks that you get vs. the US. Health insurance, paid job retraining if you lose your job among others.
Not sure about not changing careers. It is correct for college vs. non-college; you cannot change paths, and not everyone can go to college (related to grades).

Title: Re: Reusing 34/70 dry lager yeast
Post by: lupulus on November 29, 2020, 12:10:48 am
It appears that the Kunze text was first published in 1961 and it appears that texts written by Narziss are not quite as old, but are all old in terms of brewing science.  All of these texts were written before genetic sequencing, which means that anything related to yeast is based on outdated scientific information.  I am not attempting to take anything away from these brewing scientists.  They were accomplished in their day, but brewing science is not static.  To treat what they wrote as gospel in light of what has been learned in just the last ten years is, in fact, dogmatic.  The methods that they developed were based on the science of the day.
Books are summaries/ a reset of the current knowledge (as I am sure you know :-) ).
Narziss is a Professor Emeritus at Weihenstephan. The most recent book from the Weihenstephan school is that of Werner Back, still a professor at Weihenstephan.  As a research group it's probably the largest in the world. They publish mostly in "Brewing Science" but occasionally in English and American journals. 
Prost !
Title: Re: Reusing 34/70 dry lager yeast
Post by: Northern_Brewer on November 29, 2020, 12:31:34 am
Except that 2042 is a Frohberg according to Langdon et al's lager sequencing paper (https://www.nature.com/articles/s41559-019-0998-8#Sec22) last year (see Supplementary Dataset 1) - in fact they reckon all mainstream homebrew yeasts are Frohberg.

That is interesting because Wyeast 2042 has always been referred to as Miller's strain and Miller was one of the Midwestern brewers who employed Carlsberg Unterhefe No. I and the Carlsberg flask. I hate to tell you, but Langdon's data is suspect. It could just be a reporting error

All these big sequencing papers are bound to have the odd mistake in - the 1002 Genomes paper looked like they'd mixed up Artois and Orval. That's why I was careful to phrase it as "according to Langdon et al".

OTOH, the Hittinger lab are not amateurs, I suspect they're actually throwing some subtle shade as they have two entries for 34/70, on row 65 they have "W34-70" as Frohberg based on their own Peris & Langdon et al. 2016 paper and marked as "Weihenstephan 34/70" perhaps suggesting they got it direct from Weihenstephan. You're looking at row 53 where they are quoting a "W34-70" from Okuno et al. 2016 (https://pubmed.ncbi.nlm.nih.gov/26732986/), maybe Suntory have had a mixup in their library? Yes of course it's bizarre for a 34/70 isolate to be coming up as Saaz.

Edit - I've just noticed there's also a "WS3470" Frohberg in row 55 from van den Broek et al. 2015 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542246/) at Delft. You'd hope they know their Saazes from their Frohbergs given that the authors on that paper include Jan-Maarten Geertman of Heineken, hypothesised to be the original source of the entire "Frohberg" lineage.
Title: Re: Reusing 34/70 dry lager yeast
Post by: TXFlyGuy on December 01, 2020, 02:35:57 pm
I decanted about two pints of beer off my harvested W-34/70 (7th Gen), then added one quart of fresh wort. Shook it up to get it aerated, and it appeared to be coming back to life. The color went from off gray back to it's light peanut-butter like color. The aroma was nice and clean, so it was pitched into a 10 gallon batch of Munich Helles. 1 pint per 5 gallons.
Title: Re: Reusing 34/70 dry lager yeast
Post by: HopDen on December 10, 2020, 09:41:42 pm
I decanted about two pints of beer off my harvested W-34/70 (7th Gen), then added one quart of fresh wort. Shook it up to get it aerated, and it appeared to be coming back to life. The color went from off gray back to it's light peanut-butter like color. The aroma was nice and clean, so it was pitched into a 10 gallon batch of Munich Helles. 1 pint per 5 gallons.

Nice!! Keep it going as many generations as you possibly can. Nice money saver to say the least!