The delicious brew's journey begins in the boil keg, where concentrated wort extract is heated by a propane burner for 90 minutes. The beer then travels through a heat exchanger—which cools the mix to about 55˚F (13˚C)—on its way to the fermenting keg. Here, a network of Freon-chilled copper tubes pumps cool water around the keg when the temperature gets too high. After two weeks, the Device pumps the beer into a settling keg, where a CO2 tank adds carbonation. When you pull the tap, the beer travels through the cold plate, so it's chilled on the way to your glass. That's right: The Device is always ready with a cold pour and consumes no power when it's not actively serving or fermenting.