DAIRYING.

Waikato Times, Volume XXXI, Issue 2527, 20 September 1888, Page 2

DAIRYING.

TO THE IiDITOK Silt, —Everyone who has a practical knowledge of the dairy industry, will agree that those who purchase milk for butter-making, should encourage the milk suppliers to produce the richest possible milk, for rich milk not only yields more butter, but the butter is also of better quality. Again, it will be conceded that a supply of rich milk can only be obtained by allowing an increased price to correspond to the increased value of such milk. In all this, I entirely agree with "Equity," but I must take exception to the basis on which he proposes to calculate the respective values of different lots of milk. Of course no one will deny that if a given quantity of milk yielding a certain weight of butter is worth 2ld, another equal cuiantity yielding one-lifth inore butter will bo worth 3d. But the problem is to ascertain the amount of butter in the milk and this cannot be done by the means Equity suggests. People are in the habit of speaking of cream as if it were a, simple definite liquid, but such is not the case. Slum milk, whole milk and cream, all consist of small globules of butter floating in a clear liquid. When the globules are few and small we call it poor milk, when the globules are larger and more numerous it is rich milk, and when very numerous it is cream. But between the richest cream on the one hand and the mildest " sky blue " on the other there is absolutely no line of demarcation It is manifestly absurd, therefore, to talk about percentages of cream as an absolute quantity. We must have some standard which shall fairly estimate the amount of butter in the milk. The test tube under certain circumstances, and used with intelligence, will do this. For instance, in a private dairy as between quantities of milk taken at the same time—treated in the same way —and from which the cream is to be collected by setting in the ordinary way, the test tubes will indicate with sufficient accuracy the butter value of each lot of milk, But in a factory all these three conditions are wanting. Assuming thesamples to be fairly taken from all the cans— and that is assuming a great deal— yet how differently has each lot of milk been treated since it was taken from the cow. Some has coma 10 miles, some a few yards, some has been chilled, some has not, some is wartn when put in the tubes, some is cold, some will be sour in a tew hours, and some will be quite sweet. It is manifest that milk so variously treated cannot all give up its cream with equal readiness. From considerable practical experience, I do not hesitate to assert that it by no moans always follows that milk which yields the highest percentage in a factory test tube will also yield the largest amount of butter after passing through the separator. Milk which, under such conditions, shows 10 per cent, may actually contain moro butter than another lot which registers 12 per cent. Anyone who has studied this matter must have seen certain test tubes showing a large percentage of cream over a pale blue liquid. In these the butter globules have risen well. Other tubes will show a smaller percentage, but the whole of the milk will still be opaque, because the butter will not rise, even if the cream were to bo obtained. By setting, the test would still be a fair one, but in factories the cream is extracted by a separator. The great merit of the separator is that it extracts the butter globules far more perfectly and regularly than I mere setting. The test tube and setting system both act by simple gravitation ana one is a fair guide in respact of the other; but the separator acts by centrifugal force ; and the test tube is therefore not a trustworthy guide as to the value «f milk to be treated in such a machine at a factory. The following appears to mo to be the proper basis on which to estimate the value of milk. First of all let us get rid of the absurd fashion of talking about "gallons" of milk, for no factory ever measures milk by bulk. This stupid conservatism gives rise to endless disputes as to what is a gallon. When we take our milk to the factory we are told it weighs so many pounds. Why then not sell it at so much per lOOlbs ? This would enable the actual value of the milk to bo fixed with the greatest nicety. 2nd. Let the milk be tested by a centrifugal test machine. This acts in the same way as the separator, and gives an accurate measure of the value of the milk for separating. 3rd. Let a table bo prepared to correspond with the register of the test machine in which the value of each grade of milk for butter making shall be fairly estimated, Thus, if lOOlbs standard milk yield say, 41bs of butter, and is worth 2s, a grado calculated to yield 4Jlbs is worth 2s lid, and so on. For the present season, I presume we shall have to be content with the test tubes, but it is well that we should recognize the fact thai, they do not in all cases give a true measure of the value of the milk. With your permission I will deal with other points in a future letter. —Yours truly, S. Hamilton,