From Russia, with Bubbles

When people think of beverages popular in Russia, vodka is usually the first one that springs to mind. But kvas, a faintly sour-tasting, lightly fermented drink (it has a barely perceptible alcohol level that ranges from 1 to 2 percent), is perhaps just as celebrated. In cities across Russia it is sold from large portable tanks by street vendors who offer on-the-spot swigs of the drink, as well as in bottles found on grocery store shelves. Though kvas is generally drunk without embellishment (and never served iced), it finds its way into a handful of Russian dishes, including okroshka, a chilled vegetable and beef soup whose pleasingly malty taste and gentle fizz are derived from the beverage.

Kvas's name stems from the Russian verb kvasit, which means to sour. In days gone by, the beverage was often brewed in people's homes; cooks made it from water and a mixture of whatever grains were on hand (most commonly rye, and sometimes rye bread). Some versions were spiked with beets or fruit. Herbs, such as mint, were often added for an extra dimension of flavor. Nowadays, most commercially made kvas (it's widely available in the United States in shops catering to a Russian clientele) is intensely sweet—marking an effort, perhaps, by manufacturers of the drink to compete with the growing popularity in Russia of beverages like Coca-Cola. Even these somewhat inauthentic, soft drink-like versions are quite tasty, though. Russian meals—and Okroshka--aren't complete without kvas.