DAIRYING

Te Awamutu Courier, Volume 53, Issue 3808, 14 September 1936, Page 6

DAIRYING

COOLING MILK. If the dairy farm has not a good water supply let someone else have it. That is putting the matter a bit crudely, perhaps, but it is not bad advice to a young man looking for a farm. Milk goes sour because bacteria increase and multiply in it, many of them producing acids. Their rate of multiplication depends to a great extent on temperature; hence cooling acts as an antiseptic. It is not quite so effective in checking the bacteria which give rise to taints and odours as it is in controlling the rate of multiplication of the acid-forming lactic organisms, and in rare cases it may even prove a contributing cause of milk defects. W,orn coolers, on which the copper shows through the tinning, for in-

stance, occasionally give rise to socalled copper taints; and there are troubles known to the cheese-maker in which cooling proves a hindrance lather than a help. Those, however, are exceptions. They do not alter the general rule that cooling is the readiest way of making milk “ keepable.”

Engines can be cooled either by water or by air. It is not easy to air-cool milk, though cheese-makers manage to keep down the temperature of their evening’s supply by arlanging electric fans on the edges of their vats. Owing to the large surface of milk exposed this method is fairly efficient.

The simplest, and probably the oldest, method of cooling consists in standing the milk churn in a large trough of water, and in one form or another this device is still very commonly employed on small farms. Where running water is available, indeed, it meets all reasonable requirements. A modification of this plan

consists of allowing a thin stream of water to trickle over a lidded churn. For most milk sellers, however, the corrugated cooler, through which a stream of water flows, is essential. There have been some improvements in recent years in the design of coolers. The materials used are of far higher quality than years ago, while the broader furrows and bevelled ends make cleaning easier. The cooler remains, however, the most difficult of all milk utensils to keep thoroughly sterilised. It can be connected with the water supply by flexible tubing, or it can be permanently fixed in the circuit. The former arrangement has the advantage that it allows the cooler to be taken down, scalded, and sterilised, but flexible connections are apt to be leaky, and they are irritatingly shortlived.