Author Topic: Fermentation Temp vs Ambient Temp with different yeast strains.  (Read 1004 times)

Offline skyler

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I ferment using a freezer set to a temperature typically 6º F cooler than my target fermentation temperature. This has never ceased to get me within 2º of my target fermentation temperature. However, I pretty exclusively brew ales, and mostly all using the same 4-5 American and British yeast strains (Chico, Pacman, BRY-97, S-04, and 1968). I tried my hand at a pale lager for the first time in a decade of brewing (5.5 gallons with S-189, 5.5 gallons with MJ Bohemian Lager) and got active fermentation rolling at just 2º warmer than my ambient temperature. This means I am 4º below my target temperature of 52º F. I adjusted the temp control to let it get a few degrees warmer, but I am wondering if lager yeasts tend to produce less heat during fermentation than ale yeasts do. Does anyone have experience with this?

Offline a10t2

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Re: Fermentation Temp vs Ambient Temp with different yeast strains.
« Reply #1 on: June 16, 2017, 05:59:29 AM »
Not necessarily specific to lager strains. At lower temperatures, the yeast are less active, so they produce less heat.
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Offline zwiller

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Re: Fermentation Temp vs Ambient Temp with different yeast strains.
« Reply #2 on: June 16, 2017, 02:35:56 PM »
I do ambient as well but only use a 4F buffer (never measured actual temps).  I use more expressive british ale strains so I look at it as a plus if it is a little warmer.  I don't consider every xmbt as fact but last lager I did a NGP I used 3470 at my standard ale temps 64F and it worked so well I have no desire to fool with traditional lager temps nor a starter. 

I would expect the exothermic action of a saison strain to generate more heat than normal ale.  When I kill the tstat at high krausen I see near 80F. 
Sam
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Offline skyler

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Re: Fermentation Temp vs Ambient Temp with different yeast strains.
« Reply #3 on: June 18, 2017, 09:34:43 PM »
An update: While I had a substantial lag (I understand this is common with these strains), there was some visible fermentation at 48F when the chamber was set to 46F. I increased the ambient temperature of the fermentation chamber to 48F and found fermentation going actively at 54F the next day. I suppose the slower start was what lead to the decreased temperature initially. I let it ride with the ambient temp set to 48F. I was planning to let it finish, then raise to ~70F for a day or two before crashing to 30F, racking into 5 gal carboys (I don't trust my 8 gal buckets for long-term storage), and lagering it until mid-August.


Offline dannyjed

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Re: Fermentation Temp vs Ambient Temp with different yeast strains.
« Reply #4 on: June 19, 2017, 02:24:47 AM »
If you're raising the temperature at the end for a d-rest, I think 60 would be fine. No need to bring it up to 70.
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