"People have been making rye-based beverages for hundreds and hundreds of years."
kvass makes 7 cups, or 1.7 L
6 cups water
1 cup sour whey, from strained yogurt (see recipe below)
1 tablespoon kosher salt, (optional)
2 lbs beets, chopped
1 apple, chopped
1/4 cup dried apples
2 rye bread ends (optional)
whey makes 2 cups, or .47 L of whey, and 2 cups, or .47L cream cheese
2 quarts piima milk, whole-milk buttermilk, yogurt, or raw milk fine strainer
clean cheesecloth (or thin dishtowel)
1. For the beet kvass: Pour the water, salt (if using), and the whey into a large nonreactive container. Add the beets, apple, dried apple, and rye bread. Seal the container closed, using a lid with an airlock (if you have one), or cover with cheesecloth. If you have it sealed closed without an airlock, open the container every few days or so to release carbon dioxide buildup and check for mold. Place in a clean, well-protected, low-light place with an ambient temperature of 60°F/16°C to 68°F/20°C until the beets develop a mild sour flavor, about 7 to 10 days.
2. Strain the liquid, reserving the beets and liquid separately. Transfer the liquid to one or more airtight containers and refrigerate for up to 2 months. Pack the beets into one or more airtight containers, and refrigerate for up to 2 weeks if out of brine, or 2 months if covered with brine. Or, use the beets to juice for the beverage that follows.
3. For the whey: If you are using piima milk or whole-milk buttermilk, let stand at room temperature 1-2 days until the milk visibly separates into white curds and yellowish whey. If you are using yogurt, no advance preparation is required. You may use homemade yogurt or good quality commercial plain yogurt. If you are using raw milk, place the milk in a clean glass container and allow it to stand at room temperature 1-4 days until it separates. For the raw milk to separate into curds and whey properly, the air must be around 73 F.
4. Line a large strainer set over a bowl with cheesecloth or a clean dish towel. Pour in the yogurt or separated milk, cover, and let stand at room temperature for several hours (longer for yogurt). The whey will run into the bowl and the milk solids will stay in the strainer. Tie up the towel with the milk solids inside, being careful not to squeeze. Tie this little sack to a wooden spoon placed across the top of a container so that more whey can drip out. When the bag stops dripping, the cheese is ready. Store whey in a mason jar and cream cheese in a covered glass container.
5. Refrigerated, the cream cheese keeps for about 1 month and the whey for up to 6 months.