THE PREPARATION OF SOURED MILK IN THE DAIRY
There is a tendency in certain medical quarters to discourage the use of soured milk "made for profit." This view leaves out of account the fact that besides being of value in medicine, the article in question is also an excellent food, which, as we have seen, has been consumed by multitudes of people for ages in many parts of the world. There seems also to be satisfactory evidence that a larger percentage than usual of the people who make soured milk a staple of diet attain to a ripe old age. How does it become such a dangerous thing the moment the doctors get it into their hands? Of course if a man has an acute disease he places himself entirely in the hands of his medical man, and eats what is prescribed for him, or at least he ought to do so, and if he makes such a submission he is entitled at least to the comfort of being able to feel that his doctor is free from unreasonable prejudices. For the implication that an article "made for profit" is naturally suspect casts an unwarranted stigma on a large number of honourable people. There are dishonest tradesmen just as there are dishonest and careless doctors, but to saddle a whole class with the offences of a few would not be a justifiable proceeding in either case. Besides, it is not to the interest of the manufacturing chemist or the dairyman to turn out spurious cultures or bad soured milk, and on the whole we see no reason why they should not engage in the business.
The widespread use of soured milk in other countries as a regular article of diet seems to indicate that all manner of people, except those suffering from diseases which necessitate medical regulation of diet, might with probable benefit to themselves add this article to their food list; and it looks as if a good many of them intend doing so, even if scandalised doctors threaten "to abandon the cure."
The dairyman who knows his business does not need to be told of the care which is necessary to keep milk in good condition. The merely commercial consideration of avoiding loss has made him ready to inquire into the best means of prolonging the life of milk as a merchantable article. For a time he relied on chemical preservatives, but their day is now almost over, and filtration, pasteurisation, and cold storage have taken their place. Any one conversant with the trade knows how widely these methods have been adopted of late years; we may, therefore, assume that the average dairyman has at his command milk suitable for the incubation process.
The demand for soured milk is not as yet a very large one, and the apparatus so far developed for its production is meant for the treatment of small quantities. After describing the principal appliances at present in the market we propose to make some suggestions as to the construction of larger apparatus.
A firm which has given great attention to the question of maintaining fixed temperatures is that of Messrs. Charles Hearson & Co., Ltd. Their incubators for chicken hatching are known all over the world; and their appliances for biological incubation are very generally used in bacteriological laboratories. With such experience it was natural that they should turn their attention to soured milk apparatus, and the result is the "Lactobator" (Figs. 50 and 51).
Fig. 50.—"Lactobator" made by Messrs. Charles Hearson & Co., Limited, which is used for the incubation of pure culture in milk in a fairly large way. The illustration shows the "Lactobator" closed.