ps on the surface. In the
course of a few weeks, a white felting appears which later changes to
red. This slimy coat below the mold layer is made up of diverse species
of bacteria and fungi that are able to grow after the acid is reduced by
the blue mold. The organisms in the red slimy coat act upon the casein,
producing an alkaline reaction that is unfavorable to the growth of the
blue mold. Two sets of organisms are, therefore essential in the
ripening process, one preparing the soil for the ferment that later
produces the requisite ripening changes. As ordinarily carried on, the
process is an empirical one, and if the red coat does not develop as
expected, the maker resorts to all kinds of devices to bring out the
desired ferment. The appearance of the right form is dependent, however,
upon the proper reaction of the cheese, and if this is not suitable, the
wished-for growth will not appear.

INFLUENCE OF BACTERIA IN ABNORMAL CHEESE PROCESSES.

The reason why cheese is more subject to abnormal fermentation than
butter is because its high nitrogen content favors the continued
development of bacteria for some time after it is made. It must be
borne in mind, in considering the more important of these changes, that
not all defective conditions in cheese are attributable to the influence
of living organisms. Troubles frequently arise from errors in
manufacturing details, as too prolonged cooking of curds, too high
heating, or the development of insufficient or too much acid. Then
again, the production of undesirable flavors or impairment in texture
may arise from imperfect curing conditions.

Our knowledge regarding the exact nature of these indefinite faults is
as yet too inadequate to enable many of these undesirable conditions to
be traced to their proper source; but in many cases the taints observed
in a factory are due to the abnormal development of certain bacteria,
capable of evolving unpleasant or even putrid odors. Most of them are
seeded in the milk before it comes to the factory and are due to
careless manipulation of the milk while it is still on the farm. Others
gain access to the milk in the factory, owing to unclean conditions of
one sort or another. Sometimes the cheese-maker is able to overcome
these taints by vigorous treatment, but often they pass on into the
cheese, only to detract from the market value of the product. Most
frequently these "off" flavors appear in cheese that are cured at too
high