2 22 ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



gested byi bacteriologist& that an, artificial means ol: controlling this pro- 

 cess might be devised, and Prof. Storch of Copenhagen first conceived that 

 it might be possible to furnish buttermakers with cultures of the proper 

 species of bacteria to add to their cream for the purpose of ripening, 

 fcomewhat as yeast is used in brewing. This experimenter was one of 

 the first of dairy bacteriologists, and not only conceived the method but 

 put it into practical operation in Denmark. His method consisted in first 

 treating the cream by a process of pasteurization, i. e., heating to about 

 165 deg. I*'., for the purpose of destroying most of the bacteria that 

 might be present, and then adding to it a properly prepared culture of 

 bacteria whose value in producing a good flavor had been determined by 

 experiment. This method is, of course logically, perfectly satisfactory; 

 for since pasteurization destroys most of the bacteria present in the 

 cream, it follows that the ripening will be produced by the species of bac- 

 teria of which a pure culture has been prepared. Prof. Storch was soon, 

 followed in North Germany by Prof. Welgmann and others, and the 

 method adopted in Copenhagen was sioon extended more or less widely in 

 Denmark and North Germany. In Denmark it is now used almost uni- 

 formly, and in North Germany quite widely, in general dairying. Al- 

 though occasionally it has been adopted elsewhere, it can hardly be said 

 to be used in any other countries except incidentally in scattered cream- 

 eries. It is rarely used in ordinary dairying, although resorted to occa- 

 sionally for the purpose of correcting errors. 



In this country the method of the use of pure cultures has had a 

 somewhat different history,. It was introduced to our dairymen shortly 

 after its development in Copenhagen; but for some time few dairymen 

 knew anything about it, and it was hardly brought to the attention of 

 the ordinary buttermaker. Our buttermakers have not been in condi- 

 tion to pasturize their cream. For pasteurization there is needed special 

 apparatus, and the process involves considerable expense. For this 

 reason the method as suggested in Copenhagen was not very widely 

 adopted in this country. About fi\e years ago a slight change was made 

 in the process. In order to bring the subject more widely to the atten- 



