Easy to solve, tasty to drin

Easy to solve, tasty to drink
Kvass (quass, rye beer) is a traditional Slavic fermented beverage commonly made from black or regular rye bread. It is classified as a non-alcoholic drink by Russian and Ukrainian standards, as the alcohol content from fermentation is typically less than 1.2%. It may be flavoured with fruits such as strawberries and raisins, or with herbs such as mint. It is especially popular in Russia and Ukraine, but also well-known throughout Belarus, Estonia, Serbia, Poland, Latvia and Lithuania, as well as in other former Soviet states such as Georgia, Kazakhstan and Armenia. Kvass is also popular in Harbin and Xinjiang (China), where Russian culture has had an influence.