March 24 2018
My friend, Max, and I have been home brewing beer for the last several years. We’ve historically been fairly unscientific in the pursuit, though we’ve been slowly accruing better equipment and adjusting our process. Of the numerous improvements we’ve sought to make, adding a fermentation chamber was a priority on the list. Each yeast strain has an ideal temperature in which it prefers to convert soluble sugars into ethanol and CO2. In the case of lagers, the ideal temperature range is generally 7-13C. Ales generally range from 20-22C. Unfortunately just sticking a carboy full of wort and yeast into a dark closet doesn’t generally yield favorable results. If the temperature rise of the fermentation alone doesn’t transcend into yeast killing territory, the daily fluctuations of a poorly insulated apartment will. A fermentation chamber ensures fluctuations of no more than a few degrees, which will likely lead to a clean fermentation.
Building a homebrew quality fermentation chamber is pretty straightforward. It requires an insulated vessel, a heat source, a cooling source, and relays to activate and deactivate each temperature device. Max and I got a screaming deal on an oversized chest freezer from a nice lady just up the street in Boulder which solidified our vessel and cooling source. We then purchased a waterproof heat pad and mounted it on the inside of the freezer. Lastly, we built a pretty simple circuit using an InkBird temperature controller and a standard duplex electrical socket. The heat pad plugs into the top socket, freezer into the bottom socket, and the temperature probe is dropped into the vessel. The next step is to pack the circuit away into a junction box, but that’s a project for another day!