California Breweries History: Sudwerk Brewery Sudwerk Brewery's pure natural beer is brewed in accordance with the German purity law known as the "Reinheitsgebot". The "Reinheitsgebot" established in 1516 and still in effect today, requires that only barley malt, hops, water, and cultured yeast and nothing else be used in the brewing process. The ingredients used in Sudwerk's beer are purified water, barley malt from Washington, hops from Hallertau and Tettnang, Germany and cultured yeast from Weihenstephen, Germany. A slow, cold fermentation and a long maturing process are the keys to what make a great beer. It should have a palatable flavor, with a smooth distinctive body, balanced with an elegant bitterness, and a rich creamy head.