Kvass or kvas (borrowed in the 16th century from Russian квас (kvas)), sometimes called in English a bread drink, is a fermented beverage made from black rye or rye bread (which contributes to its light or dark colour). By the content of alcohol resulted from fermentation, it's classified as non-alcoholic: up to 1.2% of alcohol, according to the standard of Russia.[[http://ostapbenderx.narod.ru/Index/20/2038.htmГОСТ Р 52409-2005. П … (More on Kvass)