Kvass is a popular Slavic drink known since the Kievan Rus times. Made from rye or barley malt, it is not only very tasty, but refreshing and helpful for metabolic processes' normalization. Besides that, kvass is traditionally summer drink that perfectly slakes thirst and increases efficiency.
In order to make real kvass, you need minimum ingredients and maximum patience, for it is a very long process. Kvass's main components are rye bread, water, yeast and sugar. Some also add various herbs, dried fruits and berries to kvass.