er
adopted has been retained, because, it has resulted in such an
improvement of the cheese that the gain was much greater than the
cost, which is estimated at not over fifty cents per ton of cheese.
The whey is heated not to exceed 155 deg. F.; the hot whey serves to
scald the whey tank and as the mass of whey is usually quite large,
it does not cool to a point where bacterial growth can take place
for a number of hours. The whey is thus quite sweet when returned to
the farm and has greater feeding value. The heating also prevents
the creaming of the whey in the tank and thus avoids the soiling of
the cans with grease which is most difficult to remove.

Where compulsory legislation is in force it is generally required
that these by-products be heated to a temperature of at least 176 deg.
F. This is done so as to destroy effectually the organisms of
tuberculosis, and especially to permit of the utilization of the
so-called Storch test,[1] which enables a person to determine
quickly whether milk or whey has been heated or not.

[1] Storch (40 Rept. Expt. Stat., Copenhagen, 1898) has devised
a test whereby it can be determined whether this treatment has
been carried out or not; milk contains a soluble enzyme known as
peroxidase which has the property of decomposing hydrogen
peroxid. If milk is heated to 176 deg. F., (80 deg. C.) or above, this
enzyme is destroyed, so that the above reaction no longer takes
place. If potassium iodide and starch are added to unheated milk
and the same treated with hydrogen peroxid, the decomposition of
the latter agent releases oxygen which acts on the potassium
salt, which in turn gives off free iodine that turns the starch
blue.

=Cleaning utensils.= Various processes are applied to dairy utensils
to cleanse them. In removing visible dirt and foreign matter, much
of the bacterial life is mechanically eliminated, but most of the
cleaning processes fail to destroy the germ life in these utensils.

In rinsing, washing, or even scalding, the water is not applied at a
sufficiently high temperature to destroy effectively the bacteria.
These processes are primarily used for the removal of dirt and other
matter. To facilitate such removal, washing powders of various kinds
are frequently employed; some of these possess considerable
disinfecting action. All utensils after cleansing should be
thoroughly rinsed in clean, hot water. Even where no furthe