STARTERS 139 
mother starter for inoculation must be reduced a little 
for a few days because the germs become more vigorous 
after they have propagated several days. 
In preparing the first starter from a bottle of culture 
it is necessary to have the skim-milk sterile. For if any 
spores should remain, the slow souring would give them 
a chance to develop which might spoil the starter. More- 
over, the cooked flavor imparted by the prolonged heating 
at high temperatures does not matter in the first starter 
as this should never be used to ripen cream. The first 
and second starters prepared from a new culture seldom 
have the good flavor produced in subsequent starters. 
The cause of this in all probability is the inactive condi- 
tion of the germs and the peculiar flavor of the medium 
in which they are sent out. 
In the starters prepared later the destruction of the 
spores is not so essential as the lactic acid germs are then 
in a vigotously growing condition which renders the 
spores practically harmless. At any rate the harm done by 
them would be less than that caused by the sterilizing 
process. When milk is pasteurized at 170° to 185° F. 
for thirty minutes the vegetative germs are destroyed and 
but little cooked flavor is noticeable. 
NATURAL VERSUS COMMERCIAL STARTERS. 
Experimental tests have shown that equally good results 
can be secured with commerical and natural starters. It 
is believed, however, that the average butter maker can 
get the best results with commercial starters. ‘Too few 
are good judges of milk and for this reason are not 
always capable of selecting the best for natural starters. 
Standard commercial cultures can be relied upon as giv- 
ing uniformly good results. 
