If there's anything Lou Reed can't be accused of, it's effervescence. But that's an essential quality of many beers, particularly the bubbly wheat beer native to Germany's capital city. Berliner Weisse is a rare thing: a sour beer, intensely flavored and the embodiment of refreshment. You've read about so-called extreme beers -- Berliner Weisse is one of the originals.
Related to the lambic and gueuze traditions of Belgium, Berlin's bottle-conditioned wheat beers are made by harnessing a bacterial power most brewers go out of their way to avoid. During the brewing process, a portion of unboiled wort (grain mash) is added to the brew, essentially infecting it and making Louis Pasteur spin in his grave. This delicious madness allows a little bug called lactobacillus to take hold, turning a crisp quencher into a sparkling, puckeringly tart beer. The acidic quality, somewhere between white grapefruit juice and dry Champagne, is responsible for what some have called the world's most purely refreshing beer.
Berliner Weisse is so acidic, in fact, that if you order one in Berlin, you'll be asked, "Rot oder grün?" which is to say: "Howzabout we throw a shot of red or green syrup into your beer so you can drink it without making a face?" Even in St. Louis, if a store sells Berliner Weissbier, chances are it carries bottles of Himbeersirup (red) or Waldmeistersirup (green) alongside.
Why go through all this? Why make a beer you have to dose with fruit syrup in order to drink? Try one straight up on the hottest day of the year and then we can talk. In much the same way a squeeze of lemon or lime into a drink makes it exponentially more refreshing, or the way a big dose of citric hops brightens up a beer, the sharp sour flavor is there to ensure that you let loose with an ahhhhhhh after each sip. The beer's traditionally low alcohol level simply cements its reputation as a great quaffer.
True to form, American craft brewers have begun their own experiments with buggy beer. The practice probably won't be sweeping the land anytime soon, though. It's tricky, juggling bacteria that are normally your arch nemeses. But some are up to the challenge. There's even talk that the next beer from New Belgium will be a Berliner Weisse.
In the meantime, check out the classics from Berlin, only two of which remain: Schultheiss and Berliner Kindl Weisse. Weihenstephaner 1809 and Bayerischer Bahnhof Berliner Style Weisse are rare southern German versions, while Dogfish Head's Festina Pêche is the most common U.S. example of the style.