Primary Temperature

[Jeff]

On my next batch I plan on using some of the methods previously described to keep my primary at around 70*F. The question I have is, how do you tell what the temperature of your primary is? I have one of those stick on thermometers, but I don't think that you would get a very accurate temperature this way. It would be giving a temperature closer to the T-shirt soaked in cold water that is cooled by a fan.

Maybe I am trying to be too careful. Is there such thing as fermenting ales with too cold a temperature? Or will it just slow down the ferment time.

[ray m]

Allow me to try to alleviate your worries, Jeff. The stick-on thermomete is the only way I know of that tells you what your temperature is in the carboy. I used to be real anal about brewing stuff when I first started, but I have become less so in the last year or so. I brew year 'round, and the summers get hot & extremely humid in northern KY. I personally have never used the wet T-shirt over the carboy method---I just relax and let nature take its course. I have had fermentations get as high as 78* with no detectable off flavors. I am not saying at all that the T-shirt thing does not work or is a waste of time, because I don't doubt at all that it works very well. I just have chosen not to bother with it, and my brews have SO FAR suffered no ill effects that I can tell. Just one man's way of doing his thing.

You are right about ales fermenting at too low a temp. It's usually best to keep ale ferment temps. @ 68*-70*. If the temp. for MOST ale strains gets much below 65*, then the yeast activity slows significantly and may become dormant. The yeast at this temp. won't die, mind you----if the temp. gets too cool to the point where the yeast slows down, you just have to gradualy warm it back to a working temp. again----it's really no big deal, except your fermentation will take extra time. The same temp. should be done for bottle conditioning too.

[Fast_Eddy]

I agree with Ray M here.

I generally keep my beers in the correct ferm range for whatever yeast I'm using but unless you're brewing a beer that will be judged competitively then just relax and let it go and don't worry. If you have the means to keep the beer in the suggested heat range then go for it - I have two fridges in the garage and that makes it simple for me. If you don't, then don't sweat it - your beer will still be great. I've had ales go into the high 70's temp-wise and they were great. If you know that your ferm temps are gonna be on high end and it concerns you then switch to a higher temp yeast.

Now brewing a great lager ---- that's a different story ;)

About the wet T-Shirt thing. I think if you stick a bulb thermometer inside the T-Shirt it will wind reading the same as the temp of carboy just because the cooling effect will equally affect everything inside of the shirt. A bulb thermometer inside a wet cloth with a breeze blowing across it is actually part of a technique to determine relative humidity - it's called the "Wet Bulb temperature".