erature is increased; and hence, the amount of inoculation
is dependent on the temperature at which the starter is to be kept.
When the starter is propagated under practical conditions, it sooner
or later deteriorates, either in acid production, or in flavor, and
a new pure culture must be procured from the manufacturer. It is
impossible to give a hard and fast rule as to the length of time a
starter can be kept in good condition. It will depend on how well
the maker satisfies the conditions necessary for maintaining its
purity and strength. The use of imperfectly sterilized milk, or
dirty utensils soon contaminates it; overripening is likely to
injure the flavor. One of the most frequent troubles encountered is
the appearance of a slimy or ropy condition in the starter, although
the acidity developed may be normal and the flavor desirable. It has
been found that this condition is not necessarily due to
contamination, as was considered true in the past, but rather to
some change in the lactic bacteria themselves. If the propagation is
continued, the slimy condition will often disappear.
=Starters in "process" butter and oleomargarine.= The advance which
has recently been made in the science and practice of cream ripening
and butter production is utilized most effectively in the treatment
of cream in the renovating process. Old, soured, and stale cream
is reduced in acidity by the addition of lime. The cream is then
pasteurized and aerated to expel the odors as much as possible. A
large amount of starter is then added and the cream immediately
churned. Under these conditions, the bad flavors are materially
reduced in intensity, and desirable flavors absorbed by the fat from
the selected starter used. It is thus possible to produce butter of
good quality from cream that would at first be regarded as quite
unsuitable for butter production.
In the manufacture of oleomargarine the same principle is utilized.
The butter aroma and flavor is imparted to the neutral oils and
tasteless fats by mixing the same with a properly prepared starter.
Renovated or process butter is given a desirable flavor in the same
way.
=Wash water.= It has been found that the purity of the water used in
washing the granular butter has a marked influence on the keeping
quality. If the water is from a shallow well into which surface
water finds its way, it is certain to contain large numbers of those
types of bacteria that are found in the soil
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