Berliner Weisse is a cloudy, sour beer of around 5% alcohol by volume. It is a regional variation of the wheat beer style from Northern Germany, dating back to at least the 16th century. It can be made from combinations of malted barley and wheat, with the stipulation that the malts are kilned at very low temperatures or even air-dried to minimise colour formation. The fermentation takes place with a mixture of yeast and lactic acid bacteria, a prerequisite that creates the lactic acid taste, a distinguishing feature of Berliner Weisse; typically these are Brettanomyces yeast and lactobacteroides cultures.
By the late 19th century, Berliner Weisse was the most popular alcoholic drink in Berlin, with up to fifty breweries producing it. By the late 20th century, there were only two breweries left in Berlin producing the beer.