Heat two quarts of milk to 100° Fahr., boil together two tablespoonfuls of sugar and two of water; add this to the milk; dissolve a third of a compressed yeast cake in two tablespoonfuls of milk, add it to the milk and fill at once into bottles. Cork and tie down the corks the same as for champagne; stand the bottles upright in a temperature of 65° Fahr. over night; next morning place them carefully on their sides in a cold place, and in twenty-four hours it is ready for use. Open the bottles with a champagne tap.