By Harold McGee
German wheat beers differ from the usual Bavarian brew in four ways. First, a large fraction of the barley malt is replaced by wheat malt, which carries more protein, produces a more foamy and hazy brew, and lightens the typical malt flavor. Second, wheat beers are top-fermented like ales, and so develop more tartness and fruitiness. Third, the culture often includes an unusual yeast (Torulaspora) that produces aroma compounds not usually found in beer. These volatile phenols (vinyl guaiacol) may suggest cloves and similar spices, but also a medicinal quality like that of plastic bandages, or an animal quality reminiscent of the barnyard or stable. Finally, some wheat beers are not fully clarified, and retain some of their yeast, which gives them a cloudy appearance and yeasty flavor. German wheat beers may be called Weizen for “wheat,” Hefe-weizen for “yeast-wheat,” or Weissen for “white,” referring to their cloudy appearance.