CHAPTER XVI. 
STARTERS, OR LACTIC ACID CULTURES. 
The value of carefully selected cultures of lactic acid 
producing bacteria in cream ripening was first demon- 
strated by Dr. Storch, of Copenhagen, about twenty- 
five years ago. Since then the use of these cultures has 
spread so rapidly that few successful creameries can be 
found at the present time in which they are not used. 
Definition. Starter is the general term applied to 
cultures of lactic acid organisms, whether they have been 
selected artificially in a laboratory, or at creameries by 
picking out lots of milk that seem to contain these organ- 
isms to the exclusion of others. A good starter may be 
defined as a clean flavored batch of sour milk or sour 
skim-milk. 
The word starter derives its name from the fact that 
a starter is used to “start” or assist the development of 
the lactic fermentation in cream ripening. 
Object of Starters. Cream ordinarily contains many 
kinds of bacteria—good, bad, and indifferent—and to 
insure the predominance of the lactic acid type in the 
ripening process it is necessary to reinforce the bacteria 
of this type already existing in the cream by adding large 
quantities of them in a pure form, that is, unmixed with 
undesirable species. 
The bacterial or plant life of cream may be aptly com- 
pared with the plant life of a garden. In both we find 
plants of a desirable and undesirable character, The 
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