Dairy Notes

New Zealand Herald, Volume LXXI, Issue 21876, 11 August 1934, Page 4 (Supplement)

Dairy Notes

There has been a great deal said and written of late about the relatively small quantity of fluid milk which is consumed by children and adults in this country. Some may smile at the term fluid milk and consider the adjective quite unnecessary. But even in New Zealand milk can be bought in the form of a dry powder and also in tins as condensed milk. The milk which is so good for young people and older ones too is in the state in which it is taken from the cow, sweet, pure and wholesome, as nature intends it should be. Unfortunately it does not always remain so, and I want to tell you about a simple way in which you can prove for yourselves the quality of the milk you use. In a previous article I wrote about two kinds of germs or milk bacteria, cause milk to turn sour and later to curdle, or become thick. I also explained that one kind was good and the other bad and harmful, and that the test would show which type had taken possession and multiplied in the milk. This is the natural curd test, and is so called to distinguish it from the official curd test at the cheese factories. In the latter rennet is added to fasten the curdling as they cannot wait for it to curdle naturally. Full directions for making this test will now be given. Obtain a clear glass, wide mouth bottle of about 3oz. capacity, fitted with a good cork—a new one is best—wash both perfectly clean and boil for five minutes to sterilize or kill all germ life. When cold fill the bottle three-parts full with the milk you wish to test, cork lightly and put in a warm place, say the hot water cupboard, until the milk curdles. About blood heat is' the right temperature for the sample of milk during this process. If the milk is good, pure and wholesome there is no mistaking the type of curd it produces. It is simply a smooth solid curd without any bubbles or gas holes, or separation of whey—no liquid at the bottom—and no odour when the cork is withdrawn If the milk is extra good the curd will also have a bright velvety appearance which should be looked for and noted if present. Should the milk be contaminated by a harmful kind of bacteria the curd wiil

No. VII.

By PASTORAL

have a very different appearance. It will be more or less filled with gas holes, there will be a free separation of whey, and it will also have a very unpleasant odour. Coidd anything be simpler or easier to do? It is not nearly so difficult as some of the science work you do at school, such as determining the specific gravity of methylated spirit, or to convert glucose into sucrose, and so on. A sample of the milk one drinks should make a curd like the first one described, as should also the milk produced on dairy farms for the manufacture of either butter or cheese. When making this natural curd test it is necessary to be particular about small details. For instance, the cork must be in good condition and free frpm germs. It is best to wax it. To do this melt some paraffin wax, or good wax candle, and whilo it is very hot dip the cork in so that it becomes well coated. This will prevent any infection which may be in the cork from reaching the milk in the bottle. In a dairying country like New Zealand where the boys and girls of today will become the dairy farmers of the future' it is necessary that tha young folk should learn something about the scientific side of dairying, ana this knowledge is useful also to those ' who live in the towns.