Jamil Zainasheff, guru of all things homebrew, is oft qutoed as saying, “Proper fermentation is what sets apart great beers from just OK beers.” The first part of proper fermentation is using the right amount of yeast. The second part is temperature control. Fermentation temperature plays a crucial role in the final flavor of beer. Too cold and the yeast might not go. Too warm and off flavors are produced. Depending on the style, ingredients, and yeast, proper fermentation temperature ranges from about 45 to 85 F. Given this range, and the need to keep the beer at temperature for anywhere from 2-12 weeks, the only logical choice is to build a fermentation chamber.