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Old 04-24-2010, 02:58 PM   #1
Mar 2010
Saint Louis, Missouri
Posts: 772
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Greetings everyone.

Just had a quick question, so when in primary, and the little yeasties are doing what they do best, I have read the temp. of the beer rises to roughly 5-10 degrees more than the ambient temp of the room (ex. if you keep your house at 72 degrees (F), the temp of the primary is going to be between 77 and 82 degrees). When looking at yeast max/min temps in say the BYO yeast strain chat, is the temp posted that of the primary or of the surrounding temp?

example: WLP001 California ale from white labs says it ferments at 65-70, does that mean I would have to keep my house/brewing area at 55-65ish? cause if so, my S-04 (59-75) might be in trouble in my imperial brown as I keep my place around 70-73. Am I in trouble?

Thanks in advance.
Primary 1:NE IPA Style Saison
Primary 2: Raspberry Wheat
Primary 3: Typical Pale Ale
Up next: Lemon and Thyme Blonde

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Old 04-24-2010, 03:53 PM   #2
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marubozo's Avatar
May 2009
SW Michigan
Posts: 30,880
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The temps listed for each yeast strain should be fermentation temp, meaning the actual temp of the yeast and the beer. So yes, you ideally want to ferment in an ambient temp that's at least 5 degrees less than your target fermentation temp.

But you can bypass the ambient temp thing by using a swamp cooler, cold water bath, etc. That way you don't have to go crazy trying to change the temp of your whole house or even a whole room.

Fermenting on the high end isn't the end of the world, but you can expect a few more esters as the temp increases.

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Old 04-24-2010, 04:31 PM   #3
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defenestrate's Avatar
Sep 2008
edgewater, MD
Posts: 1,043
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i usually see 3-4 degree's higher than the ambient temps, and i dont think i've ever had over 5. your not "in trouble" but you will def get more esters like marubozo said. i would recommend the water bath with some frozen water bottles or ice backs to keep the temps under 70
(dē-fěn'ĭ-strāt') To throw out of a window.

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