and plastic
instead of crumbly or mealy. Body refers to the openness or closeness of
the curd particles, a close, compact mass being most desirable. The
color of cheese should be even, not wavy, streaked or bleached.

For a cheese to possess all of these characteristics in an optimum
degree is to be perfect in every respect--a condition that is rarely
reached.

So many factors influence this condition that the problem of making a
perfect cheese becomes exceedingly difficult. Not only must the quality
of the milk--the raw material to be used in the manufacture--be
perfectly satisfactory, but the factory management while the curds are
in the vat demands great skill and careful attention; and finally, the
long period of curing in which variation in temperature or moisture
conditions may seriously affect the quality,--all of these stages, more
or less critical, must be successfully gone through, before the product
reaches its highest state of development.

It is of course true that many phases of this complex series of
processes have no direct relation to bacteria, yet it frequently happens
that the result attained is influenced at some preceding stage by the
action of bacteria in one way or another. Thus the influence of the
acidity developed in the curds is felt throughout the whole life of the
cheese, an over-development of lactic-acid bacteria producing a sour
condition that leaves its impress not only on flavor but texture. An
insufficient development of acid fails to soften the curd-particles so
as to permit of close matting, the consequence being that the body of
the cheese remains loose and open, a condition favorable to the
development of gas-generating organisms.

~Production of flavor.~ The importance of flavor as determining the
quality of cheese makes it imperative that the nature of the substances
that confer on cheese its peculiar aromatic qualities and taste be
thoroughly understood. It is to be regretted that the results obtained
so far are not more satisfactory, for improvement in technique is hardly
to be expected until the reason for the process is thoroughly
understood.

The view that is most generally accepted is that this most important
phase of cheese curing is dependent upon bacterial activity, but the
organisms that are concerned in this process have not as yet been
satisfactorily determined. In a number of cases, different species of
bacteria have been separated from milk and cheese that hav