n the
milk or cream, or in the butter itself. The lack of flavor is looked
upon as a defect in the case of ripened-cream butter. It may be due
to insufficient ripening of the cream, or to the lack of
acid-forming bacteria that produce the desirable flavor-forming
compounds. Not all acid-forming bacteria are able to produce
favorable, flavor-giving compounds; hence, sour cream butter may
sometimes be deficient in flavor by reason of this fact.

=Putrid butter.= This specific butter trouble has been observed in
Denmark, where it was first studied by Jensen. Butter affected by it
rapidly acquires a peculiar putrid odor that ruins it for table use.
Sometimes this flavor may be developed in the cream previous to
churning. It may be caused by a number of bacteria.

=Turnip flavored butter.= Butter sometimes acquires a flavor
resembling turnips. This trouble may be due to the feeding of such
roots, the aromatic substances peculiar to them being absorbed
directly by the milk and thus transferred to the butter. Weigmann
traced a similar flavor to certain bacteria that entered the milk
from barn filth.

=Cowy odor in butter.= There is sometimes to be noted an odor in
butter as in milk that resembles that of the cow stable. Usually
this defect has been ascribed to the absorption of these odors
directly by the milk. Organisms have also been described that impart
to the butter a very similar odor. Bitter butter may be due to the
feed that is consumed by the cow, or it may be due to those forms of
bacteria that produce a bitter fermentation of the milk.

=Other abnormal flavors.= Among the numerous abnormal flavors that
have been noted in butter is one of quite frequent appearance, the
so called "fishy" flavor. It is now believed by many that this
flavor is due to the presence of small amounts of iron or copper
salts that have been introduced into the milk from utensils from
which the protective coating of tin has been worn. If the milk or
cream stored in such utensils develops any marked degree of acidity,
the acid will dissolve a small amount of the iron or copper. The
fishy flavor has not been found in sweet-cream butter as would be
expected from the above explanation. In fresh butter a metallic
taste is sometimes present. It is believed by some that on storage
this flavor changes to the fishy flavor.

All utensils used for the storage of milk and cream should be kept
in good condition so as to prevent the acid milk or crea