Kvass (Russian Fermented Rye Bread Drink)

"Kvass (kvas, quass) is probably a bit of unusual drink to this part of the globe.

Indeed, if you read ingredients list: dried rye bread, water, sugar and yeast – it probably will not strike you as something delicious. However this is one of soft drinks which is, according to Wikipedia, popular in Eastern Europe countries, especially Russia, since ancient times."

A full recipe, with step-by-step instructions for preparing this traditional Russian drink, may be found here.