LACTIC STARTERS 47 



higher temperature than the ordinary is necessary to 

 stimulate their activity. This milk should be coagulated 

 in eighteen to twenty-four hours, depending largely on 

 the uniformity of the temperature during incubation. 



65. Cleanliness. To produce a good starter, great 

 care should be exercised that all utensils coming in 

 contact with the milk are sterile. After the milk is 

 in the container in which the starter is made, it 

 should be kept covered as continuously as possible. 

 Thermometers should not be put into it to ascertain the 

 temperature. When examining the starter, do not dip 

 into it, but pour out, as this prevents contamination. 

 The cover, when removed from the container, should be 

 put in a sterile place in such way that the dirt will 

 not stick to it and later get into the starter. 



66. " Mother " starter or startoline. The thickened 

 sour milk obtained by inoculating the sweet pasteurized 

 milk with pure culture of lactic acid-forming bacteria 

 is known as " mother starter " or " startoline." 



67. Examining starter. This starter should be ex- 

 amined carefully as to physical properties, odor and taste. 

 The coagulation should be smooth, free from whey and 

 gassy pockets or bubbles. Sometimes the first few in- 

 oculations from a new culture will show signs of gas, 

 but, usually, this will quickly disappear, and not injure 

 the starter. It should have a clean sour cream odor and 

 clean, mild, acid flavor. After breaking up it should be 

 thick and creamy, entirely free from lumps. This starter 

 may have an objectionable flavor, due to the media in 

 which the organisms were growing when shipped. In 

 such cases it is necessary to carry the starter one or two 

 propagations to overcome the flavor, to enliven the 

 micro-organisms and to secure the quantity desired. 



