Question: What is the name of this traditional Slavic and Baltic fermented beverage that is used for a flavor in Fruktime and commonly made from rye bread whose colour contributes to the resulting colour of the drink?
Sentence (from "Kvass"): Kvass is a traditional Slavic and Baltic fermented beverage commonly made from rye bread, known in many Eastern European countries and especially in Russia as black bread.
Relevant evidence: Yes