Let these names roll around your mouth a moment: mumme, jopenbier, Peeterman, Cöpenicker Moll. Delicious, aren’t they? And yet the beers they designated don’t always sound equally so. Jopenbier, for example—a specialty of Gdansk, Poland—had an original gravity of near 1.200 (that’s not a typo), was spontaneously fermented, but was so poorly attenuated that it