BUTTERMILK: the liquid which remains after the separation of butter from cream. It is generally a by-product of butter manufacture. When produced under sanitary conditions and drunk fresh, it is not only exceedingly agreeable to many palates, but is very nutritious, as it contains all the cream nutrients excepting the fat. In Scot land and Ireland, it is consumed in enormous quantities as an accompaniment to por ridge and potatoes, and its use, principally as a beverage, has in the last few years been greatly extended in this country.
A pint of buttermilk of average richness contains about as much nourishment as ounces of beef. As a cheap source of protein, which comprises nearly half of its percentage of food value, it is even more deserving of notice than skim milk, to which it is very similar in chemical components—though generally regarded as inferior, it ranks higher in nutriment value. It is an especially valuable addition to the dietary when there is a deficiency of other nitrogenous food and therefore combines well with a farinaceous diet, supplying the protein lacking in cereals, etc. ( see FOOD VALUES) .
Though buttermilk contains as a rule very little milk fat, it is seldom entirely free from it, and it frequently happens that where milk is abundant and rich a consider able quantity of fat is allowed to remain in the buttermilk in the form of butter. This
increases its food value, but a careful skimming may be necessary if the milk is in tended for special dietary.
When made from fresh whole or partly-skimmed milk with selected or cultivated lactic ferments or bacteria, buttermilk contains high medical virtue—tending to prolong life by preventing decomposition of food in the bowels and avoiding the ab normal formation of gas, uric acid, toxins and other undesirable products of excessive intestinal fermentation. This result is produced by the action of the serviceable bac teria which flourish, to the exclusion of undesirable micro-organisms, in the lactic acid into which a considerable part of the sugary food elements is converted by the ferments introduced into the milk. The only important difference between buttermilk thus pre pared and the creamery product is that the natural process is accelerated and the in troduction of other and undesirable bacteria can be prevented.
Buttermilk is best kept in glass or china vessels as the lactic acid is liable to affect other receptacles.