CLEAN MILK FOR BUTTER AND CHEESE MAKING.

Otago Witness, Issue 2456, 10 April 1901, Page 4

CLEAN MILK FOR BUTTER AND CHEESE MAKING.

Whence come those organisms that cause milk to change? They are not in that part of the milk vessel where the milk is made, because under suitable conditions the milk may be taken from the cow, and it will remain perfectly sweet, so long as no organisms gain entrance from the outside. The bacteria in milk that cause it to sour and. change must therefore gain an entrance during or after the milking operation. Bacteria must then be supplied to the milk from one of the following sources : — (1) The milk in the teat ; (2) the skin of the cow ; (3) the dirt on the teats ; (4) the dirt on the hands of the milker ; (5) the air ; (6) the pails and dishes. According to Dr Weigmann, of Kiel, a very skilled bacteriologist, it is a very old experience that the first milk dray. n from each teat is much "better milked on the ground than allowed to go into the milk pail. By rejecting the first-drawn milk, butter-makers and cheese-makers found that their produce was improved in consequence. The first milk has been examined, and found to be specially rich in bacteria, which have gained entrance through the teat from the soil or litter on which the cow rested. The number of bacteria in the first milk and In the last has been counted, and has brought out this fact : that the first is very impure. The skin of all animals is well supplied with bacteria, usually of a very special kind ; and, in addition to these, the skin of the udder will always have attached to it much loose dirt that, together with offal matter, may fall into the pail. But the number of bacteria supplied to the milk from this source falls into insignificance when we consider the quantities supplied from the next two sourcss mentioned — namely, the teats of the cow and the hands of the milker. Milking with dry hands is next to impossible. No one milks with dry hands. To attempt to do so would be a mistake. But the hands need not 'fee wet. They must, however, be moist, and so must the teats. This moisture is necessary for the comfort of the cow and for the operation performed by the milker. Now both hands and teats are well supplied with bacteria. In the case of the hands this is especially the case, for are they not collecting bacteria from every substance -with which they come in contact. Washing does not remove them. They are in the irregularities of the surface and in the pores, and what operation could bstter bring them forth than the peculiar action of milking. If the hands remained merely damp no harm would come to the milk on their account, but a« a matter of fact, owing to the toughness of the teats or their small size, the hands during the milking operations became more than moist — they often become so wet thai; the exudation from them nnd from the teats drops into the milk-pail by the excess of moistiue.

There is probably one thing factory managers should and a. oul'l do, but foi the irresistible influence, to them, of the shareholders and that ih. they could reject all uuik ]id& not b-eu ihoiou^hly cooled

or atiaicv.. in coi. tains uny dnt, or is u(fe^tjd by any mihU v> hattver. But if tli.s were done, the factory managers would line a pietty lively t.me of it, and so they ai3 compelled to accept milk, ard lots ot it, too, winch they v.ould otherwise reject, ju^t to keep pence and save tioublc. M.lk suppliers tiade on the that ■what they" supply is cl'^n, although the cow s may be dirty and &cruffy, and the cans regularly cashed Mith cold water This is the common imposition, but the cows, their milker's hands, and the pa:ls are moie or le^s unclean. Many claim that it does not pay to wash uddci"=, aerate and cool milk, and thoroughly cleanse tLe can«, but they who make this claim are the suppliers of tainted milk to factories, the managers of ■« hich are expected to send out high-class cheese and butter. No manager can make high-grade butter or cheese out of tainted or imperfect milk.

Great stiess is now la:d on the influence of " starters " and pure cultures, but the filth in the supply of milk is a varying and variable quantity and requires doctoring accordingly, but is always more or less incurable. A manager of a Victorian butter factory, writing to the Leader, Melbourne, ■sa3's :— " I come to the conclusion that the power and means by which our butter makers can improve the quality of our butter is very limited. I, personally, endeavour to make the very best quality of butter every day. I spare no work or effort in order to acquire this but still I find myself facing a low standard occasionally after having taken the same pains and care, having used the same temperature, ripened to the same acidity, as when 1 got the higher results. I should have obtained the same result. What causes the difference? The milk, must be the answer. Therefore, we butter makers must look to our suppliers for improvement in their ways of milking, thereby supplying a more perfect article out of which we can make a higher grade of butter. The issue should therefore be 'no dirty cans in the future,' and when we have introduced the new era of clean cows, clean milking sheds cind good care, we will have brought in an era of better milk, more money, and more .satisfaction all around."

After a series of careful te&ts mrde by dairy experts in the home country, the remits were that, contrary to genwal belief, milk when warm, or rather during the process of cooling, more readily absorbs odours and taints than when cold. During the trials milk was allowed to stand for varying periods of time in the milking sheds near various kinds of vegetables, and at times was exposed to artificial taints, afterward readily'fecognisable in the milk, and all tended to confirm the fact that milk absorbs taints most readily when cooling directly after being drawn from the cow. This illustrates the great value of at once removing the freshly-drawn milk from the cow-houses or yards, and setting it to cool where the conditions are peifectly sanitary. A very little taint in the whole milk becomes prominent in the cream skimmed from that milk, as it is the creamy part of the milk that absorbs the taint most quickly, and holds it most persistently. Skim milk, being about 85 per cent, water, will not take up odours as readily as whole milk, nor can the water per cent, of the whole milk be considered as su.sceptible to taint by exposure to any great extent. This again shows the need of protecting the surface of the milk by having the cans closely covered after the milk has been sufficiently cooled to allow it, and then it should be kept cool and in the closed can until it reaches the creamery.