Variation in Fermenting Temps

[XLT_66]

I was wondering what the effects of say, a 10 degree F temperature variance while fermenting in the primary would/could have on a brew?

For example, when I racked to primary my buddies and I originally placed the batch in a closet in our break room at the office. However, this room is usually about 72-75 degrees and the A/C gets turned off at night. Then, after 48 hours, we decided to carefully move the batch to our server room which maintains a nice 65-66F 24/7. We hadn't thought about the nice temps in the server room until then...

It got me thinking of what temperature variances can have on the yeast and the fermentation cycle. Not only this, but what about if you were fermenting in a room that had a daily variance of say 65F at night and 75F during the day.

Any input would be appreciated. Thanks guys!

 

[permo]

The temperature variance can put stress on the yeast, cause it to drop out prematurely and be the cause of inconisistent fermentations. It is OK to manipulate the fermentation temperatures slowly to help encourage specific flavor profiles and to help a beer dry out...but I can't think of a style that would be happy about a 10 degree swing daily.

 

[maida7]

high temps produce nasty flavors. low temps cause the yeast to slow down and stop working.

in the initial phases of fermentation, the hot part of the temp swing would cause off flavors. Towards the end of fermentation the cold part of the temp swing would cause the yeast to go to sleep. But it would not wake up again when it hits the warm swing again and you'd have problems with attenuation.

Ideally you start the ferment cool and then warm it towards the end. but this is over the course of the ferment like 7-10 days.

 

[samc]

Temp swings in the room don't necessarily translate into as large a swing in a large mass of fermenting beer, so unless you actually took the beer temp it's hard to know until you taste it. The server room however sounds ideal as long as nobody is sneaking tastes!

 

[jessup]

yep 5 gal batches retain their temp pretty well. i regularly have swings from 58* to 70* in my apt, but the beer is always between 65*-68*. a big swing for the cold could cause yeasts to crash until roused and warmed.

 

[EvilGnome6]

Temp swings in the room don't necessarily translate into as large a swing in a large mass of fermenting beer

This. I leave my secondary fermenters to condition at room temperature to encourage the last bit of attenuation and let the yeast clean up. Right now my house swings between 68F and 78F from night to day but the fermenters hold between 71F and 73F.

 

[Frank99]

I'd recommend going to the White Labs/Wyeast, etc. website to check out the characteristics of your particular yeast strain as some are more sensitive than others. Also, you'll draw out different flavors/characteristics from the yeast depending on the temperature.

 

[mattd2]

Temp swings in the room don't necessarily translate into as large a swing in a large mass of fermenting beer, so unless you actually took the beer temp it's hard to know until you taste it. The server room however sounds ideal as long as nobody is sneaking tastes!

Are the lights off in there as well, I assume so since it is a server room. I seem to remember from somewhere that flourecent lamps are not too good, I could be wrong though (more than likely).