PASTEURISATION OF MILK FOR CHEDDAR CHEESE-MAKING. 289 
In the table presented above the figures represent those 
obtained from a College series of twelve ‘‘raw’’ and twelve 
‘“‘pasteurised’’ cheeses manufactured during late May and 
early June. Hach cheese was approximately forty pounds 
in weight. ; 
The table shows that the bactericidal efficiency of pas- 
teurisation was satisfactory; the average given includes 
some figures obtained from the flash method at 155° F. The 
reduction in the number of bacteria as a consequence of 
pasteurisation is marked at all stages of the process. The 
most significant figures are those of the ‘other groups”’ 
content of the raw and pasteurised milks at renneting, 
109,000 and approximately 3,000 respectively. Litmus and 
brom-thymol-blue milk inoculations showed that the pro- 
portion of harmful gas-producers of the B. coli-cerogenes 
type present in “‘other groups’? was much higher in the 
raw than in the pasteurised milk. 
Moruya Experiments. 
At the Moruya Co-operative Cheese Factory the quantity 
of milk used was much greater, the daily total varying 
from 4480 to 5530 fds. Cheese was made from the raw and 
pasteurised milks, the former serving as acheck. Hach 
batch was controlled in the way calculated to give the 
most satisfactory product. Vats and other conditions in 
common were alternately used for raw and pasteurised 
batches. The temperature at which the regenerative 
pasteuriser was run had extreme variations of 161° and 170° 
F. but did not remain more than a degree from 165° F. for 
a longer period than one minute except in the case of the 
first batch. 
Owing to flood conditions during the experiment, some 
of the milk came in somewhat stale, and the chemical and 
physical nature of the milk solids may have been affected 
by the hard conditions experienced by the cattle. 
S—December 6, 1922. 
