Pasteurization. 439 



PASTEURIZATION. 



By Jnu. a. McMillan, N.D.D. 

 ( histrtictov in Cheese Making.) 



Pasteurization is a subject that requires more serious consideration, 

 by those connected with the Australian dairying industry, than has 

 been given to it in the past. 



Time was when milk was above suspicion, but by the rapid pro- 

 gress of bacterial science within the last 30 or 40 years, it has been 

 shewn beyond the shadow of a doubt, that the erstwhile harnaless fluid 

 is an ideal breeding ground for germs of every kind, and the most 

 sensitive of all mediums for the transmission of infectious diseases. 

 It is now recognized that the dairying industry is fraught with very 

 great responsibilities, calling for much anxious thought in the conduct 

 of the trade, and making one and all engaged in the production 

 and distribution of the milk supply important factors in the well- 

 being of the community. While the social reformer may strive in 

 vain to make our lives purer and better, it is within the power of the 

 dairyman to make us live healthier lives. 



We are indebted to science for having revealed to us the dangers 

 of germ life, and putting within our reach the means whereby such 

 danger may be minimised, if not altogether overthrown. The milk, 

 when it comes from the cow, except the first few drops, and provided 

 the cow's udder is sound, is absolutely sterile. But we have the 

 difficulties to face, however, of the milk being exposed and handled 

 in a germ-laden atmosphere, and an outbreak of disease amongst our 

 herds. 



To overcome these two sources of contamination, and restore the 

 milk as nearly as possible to the immunity of bacterial life intended 

 by nature, is the duty of every dairyman, and one which he now 

 most effectually performs, if after taking every precaution to ensure 

 his supply coming from healthy cows, and being handled with the 

 most scrupulous cleanliness, he calls to his aid a careful system of 

 pasteurization, which consists in heating milk to about 160° Falir., and 

 cooling it rapidly to a temperature of about 50°. It is, however, not 

 necessary for me in this article to give details of the process of 

 pasteurizing, as every dairyman ought to know about it by this. 



The systematic application of pasteurization to the produce of the 

 dairy is due to the pioneers of scientific dairying in Denmark, who, 

 perplexed with bad flavours at times in their butter, determined to 

 know the cause, and with the help of experts, found that it was due 

 to the presence not only of bad bacteria, but also partly to weeds in 

 the pastures, &c. They adopted pasteurization and pure cultures, the 

 good result of which has been well demonstrated. Not only should 

 this method be applied to butter factories, but it would be also a 



