Therefore, in producing certified milk, only the cleanest water
available is allowed to be used in the dairy. Impure water is a common
source of the contamination of milk in such places. On some farms, the
water supply comes from a well that is too near the barn or that is too
shallow to avoid being made impure by the germs that filter into it from
the barnyard or a cesspool. If vessels in which milk is placed are
washed in such water, it is necessary to sterilize them by boiling or
steaming before milk is put into them, in order to kill the germs that
come from the water. If such a precaution as this is not observed, the
germs will multiply rapidly in the milk and, provided they are
disease-producing, will make the milk extremely dangerous.

Besides observing the precautions mentioned, it is necessary that all
utensils used in a dairy, such as pails for milking, strainers,
containers, etc., be kept scrupulously clean. Likewise, they must be
sterilized by boiling each time they are used, for, while disease germs
may be absent, those which cause the milk to sour are always present and
must be destroyed. Finally, to prevent any germs that enter milk from
multiplying, even when it is properly cared for, the milk has to be
cooled to a temperature of 45 degrees Fahrenheit or lower immediately
after milking and then bottled in sterilized bottles, sealed, and packed
in ice, within 20 minutes after milking.

35. It is by giving attention to all such matters that certified milk is
possible. Such milk, as will be understood from what has been said, is
neither a cooked milk nor a dirty milk that is processed, but a natural,
raw milk that is clean at all stages of its production and marketing.
Because of this fact, it is the best and cleanest milk to be had and may
be used without hesitation, not only by grown persons in good health,
but for infants and invalids.