ave been made to find organisms that
might be added to the cream, in order to produce the delicate flavor
characteristic of the best type of butter. Some bacteriologists have
claimed that the source of the flavor-giving substance was to be
found in the decomposition products of the nitrogenous constituents
of the milk. None of these attempts have stood the test of practical
use in creameries, and it has been demonstrated that the finest type
of butter can be made by the use of lactic bacteria alone. Formerly,
when butter was made wholly from cream soured under natural
conditions, a much higher degree of flavor was developed. Under
present market demands, a less pronounced flavor is desired, a
condition more readily met by the use of modern methods.

=Importance of butter flavor.= The importance of flavor in determining
the commercial value of butter is evidenced by the relatively high
value placed upon this factor in scoring, viz., flavor, 45 points;
body or texture, 25 points; color 15; salt 10; and package 5 points.
The factors on which butter is judged, are with the exception of
flavor, wholly under the control of the maker, but as the production
of flavor is dependent on the kind of bacteria present in the cream,
it is a far more difficult matter to control, and yet it is of the
utmost importance in determining the value of the product.

The flavor of the butter is dependent on the quality of the cream.
If this is dirty and sour, the maker has little control over the
type of fermentation, and hence, little control of the flavor of the
butter. This has led in some cases to the grading of the cream,
basing the division on the acidity, flavor, and fat content. Such
practice is entirely justifiable, as a better quality of butter can
be made from fresh, sweet cream than from that already fermented. It
is noteworthy that the quality of butter has not improved since the
introduction of the centralizer system, in which cream is shipped
for long distances.

=Control of the type of fermentation.= In the older methods of butter
making, there was little or no control of the type of fermentation
that took place in the cream. Where milk is produced under clean
conditions, and kept at ordinary temperatures, it will generally
undergo fermentation changes, due to the desirable type of
acid-forming organisms. In milk, which is less carefully handled,
the undesirable bacteria are more abundant and the quality of the
butter of lowe