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 "Fruktime"): It is made in various flavouring variants: Buratino (caramel), Tarhun (tarragon), Hand bell, Lemonade, Pear, Strawberry, Apple, Cream soda, Kvass, and Baikal (Natural).
Relevant evidence: Yes