STARTERS 143 
STARTER CANS. 
The most difficult thing in connection with starters is 
to get them just ripe when ready to use. A starter has 
its best flavor right after it has thickened. When it 
begins to show whey it indicates that the ripening has 
gone too far and should not then be used in the cream. 
The strong and curdy flavors found in butter are often 
directly attributable to overripened starters. 
It is evident that to secure the proper acidity in the 
starter from day to day, cans or vats must be used in 
which it is possible to obtain perfect control of tempera- 
ture. The improved modern starter cans answer the 
requirements. They are provided with a double jacket 
between which steam, hot water, cold water, or ice water 
may be circulated. They are also provided with power 
agitators. 
MOTHER STARTERS. 
About two per cent of the bacteria in milk are present 
in the form of spores in which condition they cannot 
be destroyed by the ordinary pasteurizing process. To 
destroy the spores, or to render milk sterile, requires pas- 
teurization on three successive days. It is for this rea- 
son that mother starters should be carried independently 
of the regular starter, the milk for which it is imprac- 
ticable to sterilize. 
A good method of handling the mother starter is as 
follows: 
Have a tinner make four narrow cylindrical tin cans, 
each large enough to hold the mother starter for one day. 
Number the cans 1, 2, 3, 4.. The first day pasteurize can 
No. 1; the second day pasteurize cans Nos. 1 and 2; the 
