Birch sap, being a delicate product, quickly loses its useful properties in a couple of days, and not everyone likes it for its insipid taste, so it is either immediately canned, or kvass is prepared, and then sent for long-term storage. One of the options for delicious birch kvass will be to prepare it based on dried fruits: dried apples, raisins, dried apricots and even dates or figs. The ingredients in the recipe are given for 50 liters of juice, and the fermentation time, depending on the conditions, should be at least five days.