FERMENTED MILKS. 17 
order to remove the grains the kefir should be strained through cheese 
cloth, and after thorough washing to remove the curd the grains may 
be dried by exposure to the sun on pieces of blotting paper. In 
this condition they are said to retain their vitality for several years, 
although many of the yeasts in the outer part of the grain are killed 
by the desiccation. It may be necessary to break up the grains with 
the fingers. When in the wet stage they should not be larger than a 
walnut. 
Kefir grains can not ordinarily be obtained in this country, but a 
good imitation of kefir can be made by carrying on simultaneously 
in sealed bottles an alcoholic and a lactic fermentation. Better 
results can be obtained by inducing the alcoholic fermentation in 
buttermilk. In this way it is possible to avoid much of the trouble 
from the formation of lumps of curd. If buttermilk is made for 
this purpose from whole or skimmed milk, careful attention should 
be given to the time of curdling and the breaking up of the curd. 
This is essential to a smooth, creamy kefir. Ordinary bread yeast 
may be used for the alcoholic fermentation, but as this yeast does 
not ferment lactose it is necessary to add cane sugar to the milk. 
(1) Obtain buttermilk from a dealer, or prepare it as directed on 
page 11. 
(2) Prepare the yeast by adding a half teaspoonful of sugar to 
a 6-ounce or 8-ounce bottle of boiled and cooled water. Add half a 
yeast cake to this sugar solution and set in a warm place overnight. 
This will give an active culture of the yeast and obviate the necessity 
of adding the yeast cake directly to the milk. This yeast culture 
should be ready at the time the buttermilk is received or, if made at 
home, at the time it is curdled. 
(3) Add 1 to 1J per cent of sugar to the buttermilk. 
On the quantity of sugar added to the buttermilk will depend the 
extent of the alcoholic fermentation. Theoretically about one-half 
of the sugar fermented may be converted into alcohol ; that is, milk 
to which 1 per cent of cane sugar has been added may contain after 
the fermentation one-half of 1 per cent of alcohol. The quantity of 
sugar added should be governed by the amount of carbon dioxid it 
is desired to have in the finished product. This should be sufficient 
to make the kefir distinctly effervescent and impart to it the peculiar, 
sharp taste of charged water, but should not be developed enough 
to blow the fluid out of the bottles when the stoppers are removed. 
Experience shows that 1 to 1J per cent of sugar will give the right 
amount of gas. This may be approximated by adding sugar in the 
proportion of two even teaspoonfuls of sugar to each pint of milk. 
Having the buttermilk and the yeast culture ready, dissolve the 
sugar in the buttermilk. 
