re must be taken in applying this method for the removal of
too much of the sugar and acid from the curd by the washing will
permit the growth of injurious forms of bacteria. The addition of
salt or of saltpeter has also been made to the milk in order to
overcome gassy conditions in the milk. In the handling of gassy
milk, the usual practice has been to develop a larger amount of acid
before drawing the whey than in the case of good milk. This was done
with the idea that acid suppressed gas formation. It has been shown
previously that this is not the case. It has also been shown by
Doane that the development of too much acid before drawing the whey
is likely to result in undesirable flavors, producing what is known
as "high-acid" or "sour" cheese.

The gas-forming bacteria grow best at high temperatures; hence,
cheese kept under these conditions are more likely to be affected by
this trouble than are those kept at lower temperatures.

The most successful method of preventing trouble with gassy milk in
cheese making is to eliminate undesirable milk by frequent testing
of the supply of the different patrons by means of the Wisconsin
curd test.

Not only gas-forming bacteria may be the cause of gassy cheese, but
the lactose-fermenting yeasts may cause similar trouble. If these
are abundant in the milk, a considerable part of the sugar may be
fermented by them, in which case, carbon dioxide gas is abundantly
formed. The cheese thus rendered gassy will present the same
appearance to the eye as where the gas is formed by bacteria, but
will have a different flavor. The odor of alcohol may be evident,
and if most of the sugar has been fermented by the yeast, the
acidity of the cheese may not be sufficient for the pepsin to exert
its digestive action.

Milk containing many gas-forming bacteria occurs most frequently in
summer. It is claimed by some that the milk of cattle pastured on
low lands is more likely to contain the gas-forming organisms than
that from cattle running on higher lands. If this is true, it must
be due to the bacterial content of the soil; the udders of the
animals become soiled as they lie on the ground, and during the
milking, the dust finds its way into the pail. Many cheese makers
think that the milk from an animal suffering from a garget may be
the cause of the huffing of cheese. This belief is undoubtedly well
founded, as some of the bacteria known to be the cause of garget are
gas-forming.

=Bi