Black IPA Fermenting too warm...

[Dan2539]

I just brewed a northern brewer black IPA using a safale US-05 yeast. The yeast has a fermentation max temperature of 75 degrees. This is the biggest brew in terms of gravity that I have made and the yeast were very active. The internal temperature of the fermenter reached 77 degrees. How much do you think the two degrees difference will impact the taste of the beer? I noticed it on the second day of fermenting and it has dropped down to an acceptable range. I'm guessing it that 77 was the peak and it was only for about a day at that temperature.

 

[neovox]

I wouldn't worry about 2 degrees especially if it was only for a short period.

 

[kevmoron]

There won't be that much of a difference between 75 and 77 to be honest, it's just important to understand the general behavior of yeasts at various temperatures. I would certainly say 77 is outside of the ideal range, as is 75. The bounds they set are somewhat arbitrary and they depend in reality on a lot of other factors such as cell count, oxygen concentration, and free amino nitrogen levels. This does not mean your beer will be undrinkable at either of these temperatures, but the yeast will throw off a lot of esters and possibly diacetyl and higher alcohols. For something as strongly flavored as a black IPA, it may not even matter, but in general if you want cleaner tasting beers, lower is better. I typically don't ferment any ales above 68 unless I am doing a saison.

In the future, sitting it in a tub with some ice jugs, draping a t shirt over it to wick up the water, and setting up a fan to blow on it would help you keep it cool cheaply.

 

[Dan2539]

Thanks, that is a helpful idea for cooling. I currently just have heating blankets so I'm sticking with ales for now. As we get further in to fall and winter it wont be an issue in the basement.