LACTIC STARTERS 



49 



FIG. 7. A simple device for 

 preparation of starter. 



the 



where mechanical power is not available. In the latter 

 the milk and starter are stirred by hand. This is the 

 kind of apparatus more 

 often found in cheese 

 factories. 



If possible, this milk 

 should be pasteurized to 

 180 F. for thirty minutes ; 

 this kills most of the bac- 

 teria and spores. The 

 milk should be cooled to 

 60-65 F., the tempera- 

 ture of incubation. This 

 temperature may be varied 

 with conditions, so that 

 the starter will be ready for use at the desired time. 

 The higher the temperature, the less time is required to 

 ripen the starter. 



70. Amount of mother starter to use. The mother 

 starter prepared the day before is now used to inoculate 

 the starter milk. The amount to use will depend on : 



1 . Temperature of milk when mother starter is added ; 



2. Average temperature at which the milk will be kept 

 during the ripening period ; 



3. Time allowed for starter to ripen before it is to be used ; 



4. Vigor and acidity of the mother starter added. 

 There is a very wide range as to the amount of mother 

 starter required, from 0.5 of one per cent to 10 per cent 

 being used under different conditions. 



Some operators prefer to add the mother starter while 

 the milk is at a temperature of about 90 F., before it has 

 been cooled to the incubating temperature. This reduces 

 the amount of mother starter necessary. 



