In the process of pasteurizing, milk is heated to 145 degrees F., and maintained at this temperature for a half hour, or longer. This produces some very important changes in the milk itself, none of which are beneficial. The process is intended to destroy bacteria which are supposed to cause disease. It does destroy some of the germs in milk, including the lactic acid bacilli, which are the natural protectors of the milk. The destruction of these lactic acid bacteria permits the milk to rot--it will not sour.
Welch's Bacillus and various putrefactive germs are present in pasteurized milk and, due to the absence of the protective lactic-acid germs, these set up putrefaction in the milk, which then becomes poisonous. Diarrhea is perhaps only the least of troubles resulting from such poisoning.
Many bacteria or their spores are not killed, even by boiling. I put no stock in the germ theory, but it was this theory that started this pasteurizing monkey-work, and I want to show its folly, even from this angle.
Pasteurization does not render milk sterile--that is bacteria-free. Not even boiling for a few minutes will do this. We are assured that 99% of the bacteria in milk are destroyed by pasteurization. This is true only under ideal conditions and these often do not prevail in commercial practice. This assurance, however, is very misleading in that it omits to mention the fact that most of the bacteria destroyed are the harmless lactic acid bacteria, while those that remain are largely the very bacteria that are said to be harmful. The statement also hides the fact that those bacteria that survive even ideal pasteurization multiply rapidly thereafter, so that within several hours after pasteurization the number of bacteria in the milk may be considerably larger than before.
In proof of this I shall appeal only to the most orthodox authorities. In their official publication: A Study of Bacteria Which Survive Pasteurization; Ayers and Johnson of the U. S. Department of Agriculture, say:
"Four distinct groups of bacteria, the acid forming, the inert, the alkali forming and the peptonizing, survive pasteurization . . . .
". . . . Streptococci from milk and cream were much more resistant than those from other sources."
The works of three noted medical authorities, Rogers and Frazier and Prucha have revealed that certain types of what the medical profession regards as dangerous streptococci and other groups of bacteria actually flourish at the temperatures of pasteurization.
Dr. Chas. Sanford Porter, who is considered an authority on milk, declares that pasteurization destroys the lactic-acid forming bacteria and that "these bacteria are not dangerous to health, and the methods of restraining or destroying them are without effect on the bacteria of consumption, typhoid, or other fevers that might contaminate milk in certain places."
Dr. Kellogg declares that: "Present methods of controlling the milk supply are by no means entirely satisfactory. This is especially true as regards the bacteriological examination of the milk. At the present time this examination usually extends no further than the determination of the total number of bacteria present except when a special research is undertaken, the number of bacteria present is no criteria whatever of the character of the milk as regards its safety to life and health. In general the greater number of bacteria present are ordinary sour germs which are entirely harmless."
Dr. Kellogg's words mean that it is not customary to make a differential count. Most of the germs present are lactic acid bacilli and not so-called typhoid germs nor so-called tubercular germs, etc. Pasteurization kills the wrong germs.
The lactic acid bacteria are often referred to as protective bacteria. Many medical men of outstanding ability think that by destroying the lactic acid bacilli, which destroy the other forms of bacteria, pasteurization may actually increase the "dangers of milk."
Discussing "Antiseptic in Milk" in The Drug Trade and Cosmetic Industry (July 1938) Wizaman and Kneiner point out that raw human and cow's milk do not support the growth of many bacteria, such as the diphtheria bacillus, streptococci and others, or permit but slight growth of these bacteria. The factor in human milk inhibiting bacterial growth has been given the name, inhibins. These men showed that this factor is inactivated by heating to temperatures lower than those employed in pasteurization. A higher temperature was found necessary to destroy/the inhibin in cow's milk in seven minutes.