COOLING MILK.
The management of milk, when once obtained, is the great practical
consideration with the farmer and cheese-maker. But the first handling
and care devolve upon the farmer; the cheese-maker's duties begin with
the delivery of the milk at the factory. Much, very much, depends upon
the treatment of the milk after milking, and the consequent condition in
which it is delivered. We will therefore begin at the stable or yard and
follow the milk through all its stages, until it is run into the
weighing-can.
Previous suggestions as to cleanliness, etc., being adopted, we find the
hot milk in the pails ready to be strained into the can standing on the
platform or in the wagon. We say "strained," because this is necessary
to absolute cleanliness, which affects the flavor, though at some
factories the patrons are directed not to strain the milk, for the
reason that poor care is so often taken of the strainer, and the keeping
of the strainer drawn tight over the top of the can prevents cooling and
hastens taint. For this reason, we would recommend the use of
strainer-pails, unless the cloth strainer can be stretched above the can
so as to allow the heat to escape and the cool air to come in. These
precautions should be observed, most certainly, if no means is adopted
for cooling the milk before starting for the factory.
The subject of cooling and airing milk has long been earnestly
discussed, and the importance of cooling, at least, we believe is
universally conceded. But how is this end to be attained, with the
thermometer indicating an average temperature of 80°, and perhaps
higher? The first and simplest suggestion is to set the can in a tub of
cold water--cold spring or well-water, or iced water--and to give the
milk frequent agitation with a dipper or other convenient article, care
being taken to stir it from the bottom, as the cold milk naturally
settles, and of course the hot milk lies on the top. Gentle agitation
secures the advantage, also, of preventing the cream from rising. This
makes trouble, and consumes a little time, but we believe the result
will well repay both.
The milk-can should, by all means, be kept out of the sun's rays, and in
a clean airy place. As to the importance of airing milk, there is a
difference of opinion. Some assert that the airing is beneficial only so
far as it assists in cooling, and that if we can succeed in cooling the
milk down to 60°, or thereabouts, immediately after milking, we shall
attain all the good results apparent from exposure to the air. All the
"animal odors," they say, disappear. Be that as it may, it is scarcely
possible to cool milk without more or less exposure to the atmosphere,
and we have never heard it claimed that any bad consequences follow this
exposure. It is possible, however, that it may more rapidly absorb
oxygen, and thus sooner sour. The probability is, that any process which
will secure the proper cooling will also afford the necessary exposure
for the escape of all animal or other odors likely to pass off in the
form of gas. Therefore, practically, it is of very little importance
whether we consider the question of airing milk, in any of the stages of
its management. So we will first look after the processes which secure
known advantages.
Several inventions for the purpose of cooling milk have made their
appearance within the past year or two. Some for the use of factories,
which seem to work quite satisfactorily, and others for the use of
farmers, none of which, we believe, have yet been received with much
favor. They are mostly too complicated, if not too expensive, and too
difficult to keep clean, to ever become generally adopted. Yet, enough
has already been developed to convince us that the desideratum, of a
satisfactory apparatus for cooling milk as fast as, or soon after, it is
taken from the cow, can be realized. The great trouble is, to make
farmers use it faithfully, if at all.
The cooling of milk as fast as milked, or very soon afterward, is the
great question now presented to farmers and cheese-makers. It is of
quite as much and more consequence, than keeping it cool at the
factory--for milk is often so far advanced in decomposition, if not
actually sour or tainted, when received, that it is impossible to work
it up satisfactorily. Some Yankee must give us a simple and cheap
apparatus that will effect the desired result. Such an invention will
greatly improve the quality and increase the consumption and price of
American cheese. But, in the absence of anything better, the can set in
a tub of water and the milk frequently stirred, would be a great
improvement on starting for the factory with hot milk. If the water can
be made to constantly run into the tub, fresh and cool, as the warm
water runs out, so much the better. Another improvement would be some
kind of wagon-cover, permitting the air to pass under it, to keep off
the sun in clear weather and keep out the rain in wet weather. The hot
rays of the sun, pouring on a can of milk for the distance of two or
three miles, perhaps--especially if the milk is not cooled before
starting--cannot fail to do it serious injury. Milk thus exposed often
has a very offensive smell when it reaches the factory-door. This shows
that it is already tainted and in a condition to injure the good milk in
the vat into which it is run, and cause a porous or "huffy" curd.
The question as to the effect of suddenly cooling milk has been somewhat
discussed; also as to how low a temperature is beneficial. Experiments
are necessary to definitely and satisfactorily settle these questions.
Our impression is that, if ice is not used, there is no danger of
cooling milk too suddenly or of getting it too cool. But where ice is
used, especially if permitted to come in contact with the milk, or even
to be separated from it only by a thickness of tin, there is danger of
chilling the particles of milk in immediate contact with the cold
surface, and causing them to prematurely decay. This would, of course,
injure the keeping qualities of the rest of the batch. So far as the
suddenness of the operation is concerned, we doubt if it would have any
material effect, one way or the other. But where any portion of the milk
is chilled, whether the whole batch of milk be slowly or suddenly
reduced in temperature, we should expect it to injure the flavor and
keeping qualities of the cheese. Some experiments, like the one made and
related by Mr. FARRINGTON, of Canada, at the last Convention of the
American Dairymen's Association, would seem to favor the conclusion,
that suddenly reducing the milk to a low temperature is unfavorable to
the production of the best quality of cheese. More experiments, as we
have previously suggested, are necessary to finally settle these
questions. But of the importance of cooling milk down to as low a
temperature as 60° to 65°, there can be no doubt; and there need be no
fear of milk being cooled rapidly enough to injure it where only water
is used in the process of cooling.