This mildly stimulant and somewhat nourishing Tartar and Russian drink is made by fermenting mare's milk. It may be quite well imitated, however, by adding to a quart of cow's milk a teaspoonful of granulated white sugar, and a tea-spoonful of brewer's yeast, and leaving the mixture to ferment in a covered vessel or corked bottle. When this change has shown itself by the bubbles of effervescence.

It is ready for use. If kept for any time, it should be in strong bottles tightly corked (the corks tied down) and in a cool place.