How Warm Can Beer Ferment?


I am entering our warm season (outside temperature 80 to 110 degrees F). We generally keep our house at about 78 degrees which is too warm for brewing ales.

I am looking for tips on how to keep brewing through the summer without using an air conditioner.

I have used a wet T-shirt on a 6.5 carboy with a small fan going to help with convection cooling. This has worked fine when the inside temps are in the low 70’s, but wondered if there is a better method when it gets warmer.


One method that works is setting the carboy in a tub of water that rotates frozen water bottles in and out of the tub. The less “economical” way is to find an old used fridge or freezer and stick a temperature controller (about $45) on it.

78 isn’t ideal but it shouldn’t kill the yeast.  Depending on the strain you’re using, you might get some funny/bad flavors.