uce the formation of acid. Where acid is
developed as a result of the growth of the lactic-acid bacteria, the
gas-producing species do not readily thrive. Another reason why acid
aids in repressing the development of gas is that the curd particles are
partially softened or digested by the action of the acid. This causes
them to mat together more closely, and there is not left in the cheese
the irregular mechanical openings in which the developing gas may find
lodgment.

Another method that is also useful with these curds is to employ salt.
This represses gaseous fermentations, and the use of more salt than
usual in making the cheese will very often restrain the production of
gas. Tendency to form gas in Edam cheese is controlled by the addition
of a starter prepared from slimy whey (lange wei) which is caused by the
development of an acid-forming organism.

Some have recommended the custom of washing the curds to remove the whey
and the gas-producing bacteria contained therein. Care must be taken not
to carry this too far, for the removal of the sugar permits
taint-producing organisms to thrive.[211]

The temperature at which the cheese is cured also materially affects the
development of gas. At high curing temperatures, gas-producing organisms
develop rapidly; therefore more trouble is experienced in summer than at
other seasons.

If milks which are prone to undergo "gassy" development are excluded
from the general supply, it would be possible to eliminate the source of
the entire trouble. To aid in the early recognition of such milks that
are not apparently affected when brought to the factory, fermentation or
curd tests (p. 76) are of great value. The use of this test in the hands
of the factory operator often enables him to detect the exact source of
the trouble, which may frequently be confined to the milk delivered by a
single patron.

~"Fruity" or "sweet" flavor.~ Not infrequently the product of a factory
may acquire during the process of ripening what is known as a "sweet" or
"fruity" flavor. This flavor resembles the odor of fermented fruit or
the bouquet of certain kinds of wine. It has been noted in widely
different sections of the country and its presence bears no relation to
the other qualities of the cheese. The cause of this trouble has
recently been traced[212] to the presence of various kinds of yeasts.
Ordinarily yeasts are rarely present in good cheese, but in cheese
affected with this trouble t