“Temperature control is often considered one of the top five steps towards brewing better beer. There are numerous methods for keeping fermenting wort at the optimum temperatures from wrapping a carboy in a blanket to keep it warm in the winter to a wet towel to keep the carboy cool in the summer. One of the challenges a fellow brewer and I encountered was how to keep two different sized carboys warm during the winter. Most fermentation temperature controllers available through the local homebrew shops have only a single temperature probe and one electric switch.”