218 CREAM-RIPENING AND STARTERS 



began to whey off at the bottom of the jar, soon after coagula- 

 tion, due to certain species of bacteria decomposing the casein, 

 invariably possessed an undesirable flavor. Samples of milk 

 which would remain coagulated for some time and whey off at 

 the top possessed a pleasant acid flavor. By selecting such 

 samples of milk for preparing natural starters, these investi- 

 gators were able to produce starters that gave excellent results 

 in cream-ripening. 



Butter made at the school that scored the highest at one of 

 the large national conventions, receiving a score of 98, was made 

 from cream that had been ripened by a natural starter. Tr^e 

 whole milk, received at the creamery when two days old, was 

 skimmed so as to contain a very high per cent of milk-fat.* The 

 object was to concentrate the fat and get rid of as much of the 

 skim-milk with its undesirable bacteria as possible, and then 

 dilute the cream with fresh milk from the herds whose milk 

 showed desirable results when souring naturally. The addition 

 of a starter ripened naturally from the above-mentioned milk, 

 ripened the cieam which produced the high-scoring butter. 



Another test was made in a national contest where dif- 

 ferent parties were placed in charge of the ripening, taking the 

 entire milk as it came in on four different days, and the same 

 method was followed with correspondingly favorable results. 

 In this contest, in which about eight hundred creameries com- 

 peted, the butter made by this method, on these four different 

 days scored the highest, third, fourth and fifth in flavor. This is 

 a further substantiation of what has been reported by various 

 investigators, S torch, Conn and others, that the flavor developed 

 depends very largely upon the species of germ life that predom- 

 inate. 



Where cream has been pasteurized and inoculated with a 

 starter containing the right organisms, the effects of the starter 

 will be more pronounced than if the cream were manufactured 

 raw or unpasteurized. This is due to the fact that the promis- 

 cuous assortment of organisms in the natural bacterial flora is 

 largely destroyed by the heating process in pasteurization. Bac- 

 teriologists do not agree as to what species of bacteria is respon- 



