nerating organisms, which are later the cause of abnormal ferment
action in the cheese (See page 186).

The influence of the air on the germ content of the milk is, as a rule,
overestimated. If the air is quiet, and free from dust, the amount of
germ life in the same is not relatively large. In a creamery or factory,
infection from this source ought to be much reduced, for the reason that
the floors and wall are, as a rule, quite damp, and hence germ life
cannot easily be dislodged. The majority of organisms found under such
conditions come from the person of the operators and attendants. Any
infection can easily be prevented by having the ripening cream-vats
covered with a canvas cloth. The clothing of the operator should be
different from the ordinary wearing-apparel. If made of white duck, the
presence of dirt is more quickly recognized, and greater care will
therefore be taken than if ordinary clothes are worn.

The surroundings of the factory have much to do with the danger of germ
infection. Many factories are poorly constructed and the drainage is
poor, so that filth and slime collect about and especially under the
factory. The emanations from these give the peculiar "factory odor" that
indicates fermenting matter. Not only are these odors absorbed
directly, but germ life from the same is apt to find its way into the
milk. Connell[49] has recently reported a serious defect in cheese that
was traced to germ infection from defective factory drains.

The water supply of a factory is also a question of prime importance.
When taken from a shallow well, especially if surface drainage from the
factory is possible, the water may be contaminated to such an extent as
to introduce undesirable bacteria in such numbers that the normal course
of fermentation may be changed. The quality of the water, aside from
flavor, can be best determined by making a curd test (p. 76) which is
done by adding some of the water to boiled milk and incubating the same.
If "gassy" fermentations occur, it signifies an abnormal condition. In
deep wells, pumped as thoroughly as is generally the case with factory
wells, the germ content should be very low, ranging from a few score to
a few hundred bacteria per cc. at most.

Harrison[50] has recently traced an off-flavor in cheese in a Canadian
factory to an infection arising from the water-supply. He found the same
germ in both water and cheese and by inoculating a culture into
pasteurized milk su