Fermentation Temperature Control

The temperature a yeast ferments at can dramatically change a beers finished profile. At warmer temperatures, yeast create a higher level of esters (fruity smelling and tasting compounds) than they do when working at cooler temperatures. Esters add a nice level of complexity to a beer, but they also take some of the focus away from the malt and hops.

The style of beer being made often determines how much ester profile you want: Most Belgian beers want a strong ester profile, whereas the majority of German & Czeck lagers take steps to minimize ester production as much as possible. Part of this manipulation of ester production is done by choosing the correct yeast strain for the style being made, and the rest is done by controlling the fermentation temperature.

Let The Controller Do The Work!:
The most ideal way for home brewers to control fermentation temperatures is to use a fridge or freezer in conjunction with a Fermentation Temperature Controller. The controller has a thermal probe that goes inside the fridge (or a thermal well in the fermenter itself). The fridge or freezer gets plugged into the controller and the controller then gets plugged into the electricity. You enter the temperature you would like to maintain and the controller automatically turns the fridge or freezer on and off to maintain your desired temperature!