224 BUTTER-MAKING. 
it has a rather disagreeable flavor. After more acid develops 
the undesirable flavor largely disappears, and the milk assumes 
a clean, desirable acid taste. The reasons for this has recently 
been accounted for by Storch, the well-known authority on 
starters. He claims that this disagreeable flavor is due to the 
action of undesirable organisms, during the first souring stage. 
As the souring progresses these germs are subdued and grad- 
ually crowded out by the desirable acid-producing types. 
In the preparation of a starter the probabilities are that 
some of these undesirable types of germs are present. At least 
it is safer to go on the assumption that they are present. This 
makes the underripening of starters just as important to guard 
against as overripening. 
Amount of Starter to Use.—The amount of starter will vary 
under different conditions. It may vary from none at all the 
as much as 50% of the cream to be ripened. The quality of 
cream is one of the factors that needs to be considered. Raw 
cream and old cream each require a large starter, especially if 
the cream is thick enough so as to permit of being reduced in 
thickness. Good pasteurized cream does not need a larger 
starter than about 10% of the cream to be ripened. 
The amount of starter to use also depends somewhat upon 
the general creamery conditions. In some creameries all the 
cream is received in a very sour and poor condition, and facili- 
ties for getting milk for preparation of starters are often very 
poor. Under such conditions it is questionable whether it 
would be profitable to use starters at all. The amount of 
starter to use chiefly depends upon the degree of rapidity of 
ripening desired, and upon the temperature of the cream. If it 
is desirable to ripen quickly, then a comparatively large starter 
(15% to 25%) should be added, and the ripening temperature 
should be comparatively high (about 80° F.). If slow ripening 
is desired, then less starter can be used. Enough, however, should 
be used to control the fermentation in the cream (about 10% 
to 15%), and the ripening temperature may be lower, between 
60° and 70° F. More starter should be used in the winter. 
