“After the lapse of three hours, when the surface of the mixture is covered with a film (of casein and fat in a non-emulsioned condition), it is again agitated for half an hour, and another bottle of skim milk—with or without warm water, according to the thickness of the milk—is added; the whole mass is again churned for an hour and a half, or longer, until the casein is well divided, and small bubbles appear on the surface of the fluid. Then the mixture, having stood for half an hour, has a fresh bottle of milk added to it, and the stirring is again renewed, with short intervals, until the Koumiss is ready, which usually happens by 10 o’clock p.m., if its preparation was commenced at 8 a.m. “The approaching completion of the Koumiss is known by a thick froth, which sometimes rises very high, forming on its surface; while the full completion of fermentation is recognised by a falling of the froth, and by certain signs detectable by the ear and hand; the process of churning becomes easier, and the splash of the drops during agitation presents a clearer and more metallic sound. The Koumiss is then poured into Champagne bottles, well corked, and left for the night at a room temperature of from 60° to 70° Fahr. Towards morning, the Koumiss is quite fit for use. Left in bottle till the next day, it becomes stronger, but is still drinkable; while, if placed in a cold room, it may be used even on the fifth day. “In order that the preparation of Koumiss may be carried on successfully, it will be necessary to put aside two bottles of the Koumiss first prepared, and to keep them for three or four days, so as always to have a bottle of four days old Koumiss in store for fermenting new portions of milk, and of replacing the used bottles by new ones.” This seems to be rather a long method of making Koumiss, compared to that given by Dr. Wolff of Philadelphia, which is excessively simple. “Take of grape sugar ½ oz.; dissolve in 4 ozs. of water. In about 2 ozs. of milk dissolve 20 grains of compressed yeast, or else well washed and pressed out brewer’s yeast. Mix the two in a quart Champagne bottle, which is to be filled with good cow’s milk to within two inches of the top; cork well, and secure the cork with string or wire, and place in an ice chest or cellar at a temperature of 50° Fahr. or less, and agitate three times a day. At the expiration of three or four days, at the latest, the Koumiss is ready for use, and ought not then to be kept longer than four or five days. It should be drawn with a Champagne syphon tap, so that the carbonic acid may be retained, and the contents will not entirely escape on opening the bottle.” Be wary in opening a bottle of Koumiss, or you may be thoroughly drenched, and have nothing left to drink, for it generates a large quantity of carbonic acid gas, so much so, indeed, that extra thick bottles should be used.