216 BACTERIA AND OTHER MICROORGANISMS IN CHEESE 
of destroying them altogether. When, therefore, the milk has a 
large quantity of lactic bacteria developing rapidly in the curd, 
the other bacteria, which might under different circumstances 
produce putrefaction, are prevented from increasing. In the 
making of cheeses this protecting action of the lactic bacteria 
becomes very important, and is, indeed, the secret of good cheese. 
The cheese remains for weeks, or even months, in a moist condi- 
tion, and there is opportunity all this time for the growth of 
bacteria. If a proper lactic organism is present at the outset, 
the cheese will be protected from the various putrefactive types 
that would otherwise surely injure it. Their presence in sufficient 
quantity is responsible for many of the defects to be noticed later. 
For these reasons, then, the cheese industry is learning the 
prime importance of a strong lactic fermentation in milk that is 
to be converted into cheese, and in order to bring this about it is 
rapidly adopting the method of using starters. Cheese starters 
are essentially identical with those used in butter-making, and 
they are used in much the same way. Home starters are fre- 
quently made and inoculated into the milk, and the use of com- 
merical starters is also rapidly growing. It is interesting to find 
that the types of lactic bacteria that are useful in butter-making 
are not always satisfactory in cheese-making. Bacteria that 
give a fine flavor and aroma to butter may produce a bitter 
taste with ruinous results when used in cheese-making. The 
use of starters in the cheese industry seems to be firmly established 
at the present time and is practically sure to extend, for it is 
one of the methods of safe-guarding the cheese against unde- 
sirable fermentations. 
“Faults” in Hard Cheese.—The value of a cheese is wholly 
dependent upon the success of the ripening. A great loss is 
entailed upon cheese-makers by an imperfect ripening, resulting 
from a variety of defects called fawlis. These are commonly 
due to the growth of certain kinds of microérganisms which do 
not grow in normal cheeses. The injury resulting to the cheese 
