The ranch. [volume] (Seattle, Wash.) 1902-1914, 1904-09-15
The Ripening of
Cheese
FROM AMERICAN CHEESEMAKER.
Cheese

different stages of curing shows that
the curing process consists principally
in the change of a complex nitrogen
Gus compound into a succession or
simpler ones. Formerly it was sup
posed that paracasein was this COM
pick compound, but discovery OF the
paracasein salts gives a better OASIS
of explanation. The formation OF par
acasein becomes, not the first step In
the curing process, but preliminary
step, followed by the building up OF
the paracasein salt of Tactic acid, the
most complex body found In cheese.
With this complex nitrogen compound
the curing process may be properly
said to begin; and while we cannot
speak as positively on this point as
on those which precede our invesuga-
tions indicate that the first breaking
down results from the action OF pep
sin-a ferment contained In rennet-
upon this paracaseln salt.
The first action of rennet is to CO.
agulate the milk and form paracase1n.
In this work it's action is greatly has
tened by the formation or the add1-
ton of a moderate amount OF acid.
This has been shown clearly by add
ing increasing small amounts OF acid
to sweet milk and noting the time re-
uuired for coagulation with rennet.
Each increase in the amount OF acid
shortens the time, the first increase
most rapidly. When the amount or
acid is one-tenth of one per cent OF
the milk the coagulation is as rapid as
is allowable in making good cheese.
Any marked increase of acid beyond
this proportion would tend to produce
poor quality, as we have already
shown. This emphasizes the impor-
lance of placing milk in the hands OF
the cheesemaker before any apprecl-
able amount of acid has been formed,
When rennet was added to pasteur-
lied milk, and cheeSemaklng and cur
ing carried on under conditions Whlch
excluded the action of other rlpenlng
agencies, such as the natural ferments
or enzymes in the milk when drawn
and the bacteria normally present or
added in STARTERS" the ripening pro-
cesses were carried on to a CONSIDER
able extent if small amount OF COM
mercial acid was added. Many OF the
compounds formed under these condl-
tions were identical with those found
upon analysis of normal cheese at dl1-
ferent stages of ripeness; and the
changes progressed in the same order
The process, however, is not complet
ed under the action of rennet alone.
While the curd ripens so that 1T would
be digestible and nutritious it does
not form those compounds which give
"nuttiness" or normal cheese flavor
the pleasant smell and taste when we
desire in the article on our tables.
When a ''starter" was used to give
the necessary acidity to the milk, the
ripening more nearly approached the
normal and some cheese flavor" de-
veloped. The biological factors-bac-
ria-introduced in the "starter" sup
plemented the purely digestive action
of the rennet and gave, in some de-
gree, all the products found in prop
erly ripened cheese.
The changes in these cheeses were
made under normal conditions and
were therefore less marked than those
caused by the same agencies under
ordinary conditions. The heating
necessary to pasteurize milk greatly
weakens it's power of coagulation,
which chemicals must be used to re-
store; and chloroform was added in
some cases also to prevent the growth
of bacteria introduced in the manipu-
lations of making. The effect of these