BACTERIAL LIFE IN MILK.

Shannon News, 24 April 1925, Page 4

BACTERIAL LIFE IN MILK.

Milk kept under ordinary conditions is short-lived; that is, changes which which make it unfit for human food rapidly set in if it is left to itself. This is true of all very soluble foods —those which contain large amounts of water and are loosely put together. When milk is first drawn it is slightly alkaline —the reverse of acid. Almost at once, however, the milk begins to change. Minute germs, which enter the milk after it somes from the cow, begin their work; fermentation sets i'a; the milk becomes acid or “sours." The sugar changes first, then the cheesy matter, and then the fats. All schemes for keeping milk or prolonging- its life are eased on the plan of first keeping the bacteria or germs out of it, and then keeping it in such condition that these germs cannot develop. The stable, the cow, the milker, the pail, and the can must all be perfectly clean. The germs hide and breed in dirt. As the milk comes from the cow it contains “cowy” or animal odours, which are. various gases dissolved in the milk. Aeration, or airing, means blowing these gases out of the milk, and this can be quickly done by blowing pure air through it or letting. it trickle in a thin stream over the surface of a cooler. A cooler is a hollow metal box of varying shape. On ,the inside cold water is kept running, while over the outside the milk runs, in a very thin stream. The bacteria that sour the milk act slowly in a cold temperature. That is why milk, meat, and similar foods, keep so much longer when packed in ice. Cold destroys most of the germs.