debeer1-5, Exercise 3: Sour styles and the purity law

Model answer:

Both are traditionally made with wheat malt as a main ingredient and, in the case of Gose, with coriander and salt, which a strict reading of the purity law (barley, hops, water and yeast) does not allow; Berliner Weisse is also soured by lactic bacteria and often served with syrup. They were revived because craft brewers and drinkers wanted older, more varied and distinctive styles than mass-produced pale lager, and because these beers were nearly lost in the twentieth century, which made them interesting to rescue.