CHAPTER XII. 
PASTEURIZATION OF MILK AND CREAM. 
The term pasteurization is derived from the discoverer 
of the process, Pasteur, an eminent French scientist, who 
is justly called the Father of Bacteriology. Originally 
this process was applied to wines to rid them of un- 
desirable fermentations. Pasteurization as applied to 
milk and cream consists in heating and cooling milk and 
cream in a manner which will destroy the bulk of bac- 
teria in them, but which will leave their chemical and 
physical properties unchanged as far as possible. 
Advantages of Pasteurization. The advantages to 
be derived from pasteurization vary with the conditions 
under which the milk is produced and the efficiency with 
which the work is conducted. If the milk comes from 
dairies where disease and uncleanliness prevail, pasteur- 
ization will prolong the keeping quality of the milk and 
also materially lessen, or entirely eliminate, the danger 
from disease germs. If, on the other hand, healthfulness 
and cleanliness receive the exacting attention which pre- 
vails on certified dairy farms, comparatively little is 
gained by subjecting milk to the pasteurizing process. 
Under existing conditions, thorough pasteurization of 
milk and cream is desirable, for several reasons: In 
the first place average unpasteurized market milk con- 
tains Over 1,000,000 bacteria per c. c., and none of this 
can be guaranteed free from pathogenic organisms. 
Milk that comes nearest to being free from pathogenic 
and other classes of bacteria, is certified milk, but even 
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