Buttermilk

True buttermilk, which is common on farms, is seldom found in commerce. Unless produced where sold, its genuineness may be a matter of question. Those who are familiar with the genuine article state that the delicacy of its flavor, its consistency, etc., are much superior to the socalled buttermilk of commerce. The composition of the two articles is practically the same. When skim milk, the cream having been removed by the separator, is allowed to sour, it is said to resemble ordinary buttermilk, and the fluid which goes by the latter name, sold extensively throughout Greater New York, is said to be sour skim milk.

Metschnickoff Artificially Soured Milk

The announcement some years ago by Metschniclcoff that the foregoing products were of very great hygienic and therapeutic value in disinfecting the intestines has resulted in the wholesale production of a substance which differs from ordinary sour milk in that it is prepared from a pure culture of lactic-acid germs. This product is doubtless destined to replace the older ones on account of its freedom from undesirable forms of bacteria. The technique for preparing it, devised originally by Metschnickoff himself, also places it in a higher class than the older preparations. The pure culture is sold in the solid form as Buttermilk Tablets.

Fermented Milk

Milk which has been fermented is really a derivative of native milk, and in parts of Europe and Asia constitutes an important article of diet. The fermentation is either the lactic alone or lactic and alcoholic together.

The ferments used consist chiefly of various "leavens" or cultures which cause lactic acid fermentation. People who have subsisted on this milk for centuries simply use a portion of old fermented milk to leaven fresh milk. These leavens vary considerably in composition, and the milk used may be from one of several domestic animals. Some leavens contain yeast germs, as that alcohol may or may not be present. The native preparations which have been imitated in this country are kumyss, kefir and matzoon.

Kumyss was prepared originally from mares' milk. The leaven contains lactic acid germs and yeast. The product therefore contains lactic acid, alcohol, and carbonic acid gas, representing an acid, effervescing, mildly alcoholic beverage. The casein curd is finely broken up and partially digested. Kumyss has been imitated in America by adding yeast to milk and allowing fermentation to proceed twenty-four hours or over.

Kefir was made originally from cows' milk with a leaven of kumyss. This has been sold in tablet form like the rennet ferment. Kefir resembles kumyss so closely that no further description is necessary.

Matzoon differs from the preceding chiefly in containing no alcohol.

Modified Milk

Modified Milk is milk containing definite proportions of fat, sugar, proteids, etc., put up usually according to the formula of a physician, who prescribes the quantity of the different constituents he desires.

For sick children and in convalescence it is of great value to obtain a modification in which the composition is definite and accurate. It can then be known what mixtures will agree with the patient.