700 g of rye bread, 6 liters of water, 300 g of sugar, 40 g raisins, 1 tsp. citric acid or juice of ½ lemon, 5 g of yeast, diluted in a half glass of warm water with 1 tbs. flour and 1 tsp. sugar.
Rye bread cut into small pieces and dry in the oven. Pour over bread, hot water, mix well. Cool the wort to a temperature of fresh milk and add yeast and leave for 12 hours.
Thereafter, the liquid filter and added sugar, raisins and lemon (available citric acid). Mix and leave for another 12 hours. After that, pour into bottles, tightly resealed and put into a cold place. Kvass will be ready in a day.