PASTEURISATION OF MILK FOR CHEDDAR CHEESE-MAKING. 285 
NOTES ON THE BACTHRIOLOGICAL ASPECT OF 
PASTHURISATION OF MILK FOR 
CHEDDAR CHEHSE-MAKING. 
By J. K. MURRAY, B.A., B.Sc., (Agr.) 
Lecturer in Bacteriology, Hawkesbury Agricultural College. 
(Communicated by R. D. Wart, M.A., B.Sc.) 
[Read before the Royal Society of N.S. Wales, December 6, 1922. | , 


EXPERIMENTS have been conducted by Mr. T.H. Atkinson 
of the Dairy Branch, Department of Agriculture and the 
writer of this paper with a view to determining for this 
State the influence of the pasteurisation of milk on the 
yield and quality of cheese. Work along similar lines has 
been done elsewhere, but few bacteriological data are 
available and none have apparently been published in 
Australia. 
The figures now given are recorded from work done at 
the Hawkesbury Agricultural College and continued at the 
Moruya Co-operative Dairy Company’s factory by courtesy 
of its directors. The results are those obtained during the 
Winter and, presumably, would have been even more 
marked had they been the record of Summer experiments. 
General. 
Pasteurisation has for its object the killing of the great 
majority of the bacteria present in the raw milk, thus pre-. 
senting a relatively germ-free milk for inoculation by 
starter with those bacteria which experience has shown 
to be intimately linked up with good quality in cheese. As 
indicated ina previous article,** the alternative is a much 
improved bacterial quality of the raw milk. Careful 
observance of the factors necessary for such an improve- 

* Reference is made by number to literature cited p. 297. 
