Effects of no temp. control

[fiber22]

Hi Folks,

I am curious if my lack of being able to control temps during fermentation will have much of an impact on the taste of my beer. I ask this because I have had an off flavor in a beer of mine and although I can't pinpoint what it is exactly, my best guess would that it is caused by fermentation temps.

My basement sits pretty steady around 63. At high krausen the fermentor probably increases about 3 to 4 degrees. Once fermentation subsides it falls back down to 63-64. Is this much of any issue or would I be splitting hairs trying to fix this and hold the fermentor at it's peak temp like 68 to finish out the fermentation process.

 

[chocotaco]

Depending on the yeast, 68 seems like a fine temp to me. Are you sure that the beer doesn't get higher than that? AFAIK high fermentation temps are a bigger problem than a few degrees of swing under 70.

I would put the next one in a water bath inside a party tub (up to the level of beer in your carboy) at 63 in your cellar. Measure the water temp with an instant-read or probe thermometer every so often during the first 72 hours of fermentation and make sure it is what you expect. The water bath will help to keep the temperature of the beer from rising far above the temp of your basement, and it will more or less be the same temp as the beer at all times. Thus you can measure the temp of the water easily and be pretty sure of the beer temperature. Then compare the results of that batch to the one you were wary about.

 

[E_Marquez]

My experience is yes..temp matters a lot.

Though 63 ambient temp is pretty good for a lot of yeasts and beers, from what i have learned here and at each yeast manufacture I have used.

Would help if you posted the specific beer, it's recipe, and yeast pitched, wort temp when you pitched ect.

 

[jro238]

Trying to nail down that off flavor would be the most helpful info here.

Per your question: It depends a lot on your choice of yeast and original gravity. A good number of yeasts will be nice and happy in that temp range. It is possible that with some higher gravities, the cold may affect attenuation (yeast might poop out early) but again, all depends on yeast. I personally brew a lot of belgians so I try to keep my temps during fermentation a bit more stable around 67-68 (then just let it go up as it pleases after fermentation is mostly complete).

It also sounds like you don't know exactly how warm your fermentation is getting. Get a stick-on thermometer to put on your fermenter so you can make sure your beer is really only getting to 68 and not actually 72 or 73.

 

[kh54s10]

You might be experiencing only a few degrees of temperature rise due to the fermentation but it is likely that you are really getting 5-10 degrees. If ambient goes to 65 and you get to 75 you may get fusel alcohols which will give a harsh "bite" to the beer.

One of the best things that you can do to improve your beer is to control fermentation temperature.

 

[chocotaco]

Could also be how much you pitched, oxygen levels etc.

What yeast was it, how much did you pitch, how old was it, and did you/how did you aerate. I think those are the four important questions you didn't answer in your OP.