Krausening is a traditional German method for carbonating beers without using sugars or other adjuncts. Instead actively fermenting malt wort is added to the fermented beer to provide the malted sugars needed for carbonation. The “Reinheitsgebot”, or German purity law, originated in Bavaria in 1516. It specifies that beer may only be made from the three basic ingredients: malt, hops, and water.
