What is Reinheitsgebot?
1.
A somewhat overrated Bavarian beer purity law requiring beer to be made from barley, water, hops, yeast, and nothing else. Kept southern German beer at a high standard until 1987, and still honored by German brewers today even though the EU forced its repeal, but ran lots of northern German brewers (who made funky Belgian-style beers) out of business.
