Bread cut into very thin slices, which are roasted in low oven until browned, like biscuit. Slices are broken into small pieces and pour 2 liters of boiling water. Leave for 4-5 hours in a warm place. The yeast was suspended in a little water and mixed with sugar. Bread is filtered first through a strainer, then through gauze. The fluid is mixed with yeast and left for 10-12 hours at room temperature. Run into bottles in which optional put a few raisins, mint leaves, strawberries or whatever fantasy you born, but may be left natural. The bottles are closed well and stay three days of cold - cold in the refrigerator or pantry, basement. The leaven is very refreshing, but due to the lactic acid bacteria aids digestion. Note - contains between 0:05 to 1:44% alcohol.