Kefir can be made from the milk of different animals, but it is generally made from cow's milk. Fermentation is excited by the presence of the kefir, which is a species of mush-room, white when fresh, and yellow when old and dry, compact, elastic, and about one-fiftieth of an inch in diameter.
Chemically it is composed of water, fat, peptone, and nitrogenous material.
Examined microscopically it is composed of the rods and cells of beer-yeast.
It is found in the mountains of northern Caucasus near the snows. The natives believe that it is produced by the bushes which grow upon the mountain-tops. It is probable that the first origin is in the great number of bacteria which circulate in the atmosphere, and whose soil of development is furnished by the curds of coagulated milk.
At the beginning of the preparation of kefir the grains should be allowed to swell in tepid water for five or six hours-two teaspoonfuls to a tablespoon ful of kefir grains; they should then be washed in cold water and put in half a glass of fresh milk, which is changed every three hours. The grains, which were yellow, become white, and are then ready for the preparation of kefir.
This is done by placing the white grains in a quart of fresh cow's milk, and the whole placed in uncorked bottles and exposed to a temperature of about 45° F., and frequently shaken. The milk begins to ferment soon, and in seven or eight hours the mass is fermented. The kefir grains are removed by filtering through muslin, the liquid replaced in bottles, which are only partly filled, and carefully corked.
The milk is left at a constant temperature, and shaken every two or three hours. Fermentation continues in spite of the absence of the ferment, and in twenty-four hours the drink is ready. The grains of kefir may be washed and used indefinitely.
Kefir is richer in albumen than koumiss, less alcoholic, and less acid.
The following table of analysis shows the composition. of milk, koumiss, and kefir:
|Sugar of milk||41||22.0||20|
|Water and salts||873||918.3||905|
The American Journal of Pharmacy, Vol. 59, 1887, was edited by John M. Maisch.