Fermentation temperature control is one of the most valuable improvements one can make in the world of homebrewing. However temperatures vary wildly, sometimes even within the same batch. For example lager yeast performs best at cooler temperatures but some brewers like to gradually warm up the beer to reduce the risk of off flavors appearing in the beer. Whereas some newly discovered yeasts perform best at very warm temperatures.

Temperature control systems typically used at the homebrew scale rely on two independent systems to heat and cool a fermentation: usually a resistive jacket to provide heat and a glycol chilled loop to provide cooling. Besides being energy intensive, this is also energy inefficient because heat dumped through the glycol chiller could be used to heat another fermentation.

Using TEC modules to intelligently move heat between fermentation vessels could reduce energy use and provide more repeatable temp control than existing methods.