Home Brew Forums

Home Brew Forums (http://www.homebrewtalk.com/forum.php)
-   Fermentation & Yeast (http://www.homebrewtalk.com/f163/)
-   -   Yeast mutate based off temp (lager starters) (http://www.homebrewtalk.com/f163/yeast-mutate-based-off-temp-lager-starters-352456/)

KaSaBiS 09-05-2012 11:30 PM

Yeast mutate based off temp (lager starters)
 
Specifically this is towards my lager step starter. I need to prop a ton of yeast for my 10 gallon munich dunkel. I have a ferm chamber that I am thinking about using for my yeast starter at pitching temp, which will be approx 47*F.

Common procedure is to keep yeast starters at room temp to speed up exponential growth. But in my research yeast mutate based off of wort and temp. This may not be an issue on a homebrew scale but still something Im concerned with, due to my obsession in our hobby.

It wouldnt bother me to let my starter take an extra day to complete its growth phase at pitching temp. All I see is benefits, as there will be no shock on my yeast when I pitch cold, except for a little longer length of time for growth cycle per step. which is countered my a shorter lag time.

Anyone agree with me to keep my starters cool? I understand that pitching warm for a starter is fine as the starter wort is decanted, but then the yeast are conditioned to ferment at that temp as well. I just want to keep the little boogers happy!

Thanks in advance!

Buna_Bere 09-05-2012 11:46 PM

Dan Gordon from Gordon Biersch agrees with you. He talked about it on an episode of the Sunday Session on The Brewing Network, and mutations are the exact reason he gave, and they propogate a fresh pitch for every batch.

KaSaBiS 09-05-2012 11:49 PM

I noticed quite a bit of contradictary comments on certain topics on the BN, and this was one that I couldnt really sift through. I will dig up that episode and relisten. Cheers.

jtejedor 09-05-2012 11:58 PM

I wonder if wyeast and white labs grow lager yeast at lager temps. That said I haven't seen many people bring this up as a real big issue however I can't fault the logic behind it. My thought is that the starters will take much longer to ferment completely and like you I usually have to do quite a few steps to get enough yeast for 10 gallons.

KaSaBiS 09-06-2012 12:04 AM

Quote:

Originally Posted by jtejedor (Post 4389873)
I wonder if wyeast and white labs grow lager yeast at lager temps.

interesting question. part of me thinks that they would prop at higher temps, as they are a business, and time=money, but then again that mutates their authenticity of their strains prior to shipping. Sounds like a question for Chris White. Ill try and shoot that exact question to them and post the reply here

Denny 09-06-2012 08:30 PM

Quote:

Originally Posted by KaSaBiS (Post 4389883)
interesting question. part of me thinks that they would prop at higher temps, as they are a business, and time=money, but then again that mutates their authenticity of their strains prior to shipping. Sounds like a question for Chris White. Ill try and shoot that exact question to them and post the reply here

AFAIK, no they don't and you shouldn't either. You're growing yeast, not making beer. Yeats mutation takes time and higher temps than room temp. Just because a commercial brewer does something is not necessarily a reason for homebrewers to do it.

KaSaBiS 09-06-2012 11:53 PM

Quote:

Originally Posted by Denny (Post 4392387)
You're growing yeast, not making beer

That I understand. Hence my decanting. but What my question is, wont the yeast get comfortable budding at 70F and become lazy or struggle to adapt when they have to perform the same work at 20F lower than what they are used to? Perhaps it would shorten the lag time on a lager if their is no shock.

being aware its easier for yeast to work as things warm up, vs cool down. perhaps I should make the starter warm, crash cool/decant at 33, then let it warm up to pitch temp (which will warm em back up and prep them) for a day or so, then pitch at 45F and let it warm up to 50F and hold for the duration.

Quote:

Originally Posted by Denny (Post 4392387)
Yeast mutation takes time and higher temps than room temp.

I am not trying to replicate pro brewers in my tiny 10G batches, but in brewerys they dont indefinately repitch the same yeast due to the mutation that goes on, even at steady temperatures. I know we are talking 12 repitches in the pro side of things, but that implies when they hold steady temps, that the mutation is based soley on time (2 month life cycle perhaps?)

Thanks for the response, and I am aware I could be overthinking all of this, but it is stil intruiging to think about

Denny 09-07-2012 02:34 PM

Quote:

Originally Posted by KaSaBiS (Post 4392939)
That I understand. Hence my decanting. but What my question is, wont the yeast get comfortable budding at 70F and become lazy or struggle to adapt when they have to perform the same work at 20F lower than what they are used to? Perhaps it would shorten the lag time on a lager if their is no shock.

being aware its easier for yeast to work as things warm up, vs cool down. perhaps I should make the starter warm, crash cool/decant at 33, then let it warm up to pitch temp (which will warm em back up and prep them) for a day or so, then pitch at 45F and let it warm up to 50F and hold for the duration.



I am not trying to replicate pro brewers in my tiny 10G batches, but in brewerys they dont indefinately repitch the same yeast due to the mutation that goes on, even at steady temperatures. I know we are talking 12 repitches in the pro side of things, but that implies when they hold steady temps, that the mutation is based soley on time (2 month life cycle perhaps?)

Thanks for the response, and I am aware I could be overthinking all of this, but it is stil intruiging to think about

I think you're laboring under a misconception. What makes you think that the yeast care about propagating at 70 and fermenting at 50? I grow lager starters at room temp. When they're fermented out, I cold crash them for a couple days, decant, and pitch directly from the fridge. I do that for lagers at 50F and ales at 62F. I get fast starts and clean fermentations. I also think you're obver generalizing about what commercial breweries do. I'm not sure any of the ones I'm acquainted with reuse the yeast 12 times, althgh there may be some who do. Rogue is the brewery I'm most familiar with and AFAIK there is no number set for reuse. It depends on how the yeast is doing. When it's done they simply order more from their bank at Wyeast.

stjackson 09-07-2012 05:00 PM

Interesting that I should read this today as the epidode of The Jamil Show I was listenening to on the way to work this morning mentioned this very subject. Jamil said he grows yeast at room temp, cools, decants, and pitches cold. He said that mutation doesn't become a big problem unless your starters are working in the 80s. I'm not saying he's 100% right, but he certainly has the experience to convince me that growing starters of all kinds at room temp is not going to harm my beer, at least not on the scale at which I brew.


All times are GMT. The time now is 06:38 AM.

Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.