PASTEURISATION

Sun (Auckland), Volume II, Issue 508, 10 November 1928, Page 7

PASTEURISATION

EFFECT ON MILK HEALTH DEPARTMENT PAPER Milk should be kept in the coolest place available preferably in some simple form of home-made dust-proof cooler, says a Health Department publication. Access of dust should be avoided, chiefly by ensuring that the house is as free from dust as cleanliness can make it. The milk should always be put in clean vessels; a jug which has held milk should be rinsed out, first in cold water and then washed in hot water and soda, and for babies’ milk it should certainly be finally scalded with boiling water and placed upside down without drying on a rack to drain. A good method of protecting milk in jugs or bottles is to make net covers of white material known as “mosquito netting” cut large enough to cover the mouths of the different receptacles. To the edge of those circular pieces glass beads should be sewn, the weight of which will tighten the net over the edge. These net covers should be kept scrupulously clean. The germs of disease get into milk so easily that some reliable way to purify the milk is essential. The scientist, Pasteur, who saw the need of an easy, cheap, and reliable way to destroy these germs, discovered the process now known as pasteurisation. Milk is heated to a temperature of 142 to 145 degrees Fahrenheit, and is held there for 30 minutes, a higher temperature or a longer time is not necessary; a lower temperature or a shorter time may not kill the harmful bacteria. Then, after the milk has been heated in this manner it must be chilled immediately and kept cold. Pasteurisation does not make poor milk rich or dirty milk clean, its only object is to destroy injurious germs. It neither harms nor improves the milk itself, except that it lessens the amount of anti-scurvy vitamin and

destroys injurious germs. Except for the slight reduction of anti-scurvy vitamin there is no more objection to pasteurising milk than there is to broiling beefsteak. The milk remains just as digestible aud just as nutritious as raw milk. It still retains also many of the harmless and hardy forms of bacteria which continue to grow and multiply so that the milk sours and curdles just as raw milk does although more slowly. Pasteurisation can be effected in the home by heating the milk in a double boiler keeping it between 142 and 145 degrees Fahrenheit for quarters of an hour. If you have no thermomoter bring the milk just to the boiling point to make sure the harmful germs are killed, then chill it quickly and keep it cold and covered.