Kvass is a real Russian drink. It is a product of fermentation on the basis of rye bread with added sugar and raisins. Earlier it was only home made drink but now in Russia and the countries of the former USSR there are many factories that make kvass. Kvass contains some alcohol (0.5 to 2.2%), but you will not drunk! Kvass is so popular in Russia that Coca Cola has also become to produce kvass.
How to make kvass?
How to make kvass?