14 BULLETIN 319, U. S. DEPARTMENT OF AGRICULTURE. 
(4) Kepeat the process, using a teaspoonful of the freshly curdled 
milk to inoculate the heated and cooled milk. 
Buttermakers in the Northwest make a very refreshing and nu- 
tritious drink by adding sugar and lemons to buttermilk. As the 
casein is already precipitated, the acid juice of the lemon has no 
effect. Slightly more sugar and lemon juice are necessary than in 
making ordinary lemonade, and the mixture should be well iced. 
KEFIR. 
Fermented milks have evidently been extensively used for many 
centuries by the people of southern Russia, Turkey, the Balkan coun- 
tries, and their neighbors. The natives have no records and few 
traditions of the origin of the milks they use, and it is probable that 
their preparation and use developed gradually by accident and cumu- 
lative experience. One of the first of the fermented milks known to 
Europeans was the kefir, made from the milk of sheep, goats, or 
cows in the Caucasus Mountains and neighboring regions. Kefir 
differs from most of the fermented milks of the Mediterranean coun- 
tries in that it is made from a dried preparation and contains con- 
siderable quantities of alcohol and gas. Kefir is made by many tribes 
under varying names, as " hippe,*' " kepi," " khapon," " kephir," 
" kiaphir," and " kaphir," all of which are said to come from a com- 
mon root signifying a pleasant or agreeable taste. 
For a large part of their food the mountaineers of the Caucasus 
depend on kefir, which they prepare in leather bottles made from the 
skins of goats. In the summer the skins are hung outdoors, either 
in the sun or in the shade, according to the weather, but in winter 
they are kept in the house. The bags are usually hung ■ near a 
doorway, where they may be frequently shaken or lacked by each 
passer-by. Fresh milk is added as the kefir is taken out, and the 
fermentation continues. Made and propagated in this way, foreign 
bacteria become mingled with the essential bacteria of the grains, 
and abnormal and frequently disagreeable flavors result. "When the 
milk is drawn off, in order to prevent the escape of gas, a string is 
first tied around the neck of the leather bottle, so that the small part 
wanted for use is held between the stricture and the opening. In 
the villages and the low country kefir is made in open earthen or 
wooden vessels, and most of the gas escapes. 
Small, yellowish, convoluted masses are observed in kefir, which 
are called seeds or " grains.'' These grains consist of a central fila- 
ment of two parts, of which the outer spreads out, forming the con- 
voluted polyp-like exterior. These parts are built up one upon an- 
other, giving the large grains a coral-like appearance. The central 
part is made up of a mass of bacterial threads. In the outer layer 
