Wikipedia
Fassbrause , literally "keg soda", is a non-alcoholic or alcoholic (depending on the brand) German drink made from fruit and spices and malt extract, traditionally stored in a keg. Fassbrause is a speciality of Berlin, where it is sometimes called Sportmolle. (Molle used to be a term for "beer" in the Berlin dialect.)
Fassbrause is about the same color as some beers, and usually tastes like apples. The taste is strongly reminiscent of the Austrian drink, Almdudler, except that Fassbrause is less sweet, and not quite as spicy.
A variant of Fassbrause, the so-called Rote Fassbrause ("red keg soda"), which is available in some of the new states, but not in Berlin itself, appeared in the 1950s. This variant was available in the German Democratic Republic (GDR) prior to German Reunification and tastes like raspberries.
Another non-alcoholic variant has been produced in the United States since the 1960s under the name " Apple Beer".