Are you dreaming about brewing beer at home. No problem with that, you just have to control many parameters during brewing like temperature, ingredients. Everything has to be done precisely in order to end up with great drink. This is why BrewTroller was developed, which automates most of brewing process including heating, pumps and valves.
BrewTroller is based on Sanguino (aka Arduino) platform, while project itself is completely open source. Author continues to improve platform and seems that next version is coming up with USB support. Happy brewing!