Cut the bread into pieces. Make crackers out of them. Place the crackers in a three-liter glass jar. Pour boiled hot water into it. Pour 2 tbsp. l sugar and yeast. Stir the food in a jar and cover it with gauze in several layers, secure with an elastic band around the neck.
Put the jar in heat and cover with a cotton cloth. After 2 days, put the jar in the refrigerator. After cooling the kvass, it must be filtered and sweetened to taste with sugar. Yeast rye kvass is ready.