Originally known as “steam beer,” this style originated during the California Gold Rush. San Francisco brewers had to their wort with some MacGyver-like methods, and the cool air off the Pacific was a natural chiller. Wort pumped into open vats on brewery roofs let off steam as it cooled and dropped temperatures to some of the highest ranges tolerated by lager yeast. While we admire the ingenuity, we’ll take modern refrigeration any day.