218 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



the manufacture of Cheddar cheese from pasteurized milk has been 

 continued. The following points in this connection are being 

 investigated : 



(1) The practicability of this method in the hands of experienced 

 cheese makers. 



(2) The possibility of appl3dng the method daily throughout the 

 year to all sorts of milk wliich may lawfully be used for cheese 

 making in Wisconsin. 



(3) The precautions to be taken in the use of tliis method. 



(4) Whether the curing of pasteurized milk cheese can be safely 

 conducted at a higher temperature than that of raw milk cheese. 



(5) The suitability of this cheese for various markets. 



(6) The loss in weight during shipment and sale of cheese in the 

 South. 



(7) The relative quality of raw milk cheese and pasteurized milk 

 cheese made from the same milk supply. 



(8) The cost of pasteurization and the cost of manufacture when 

 pasteurized milk is used, as compared with the same costs when raw 

 milk is used. 



It is hoped to establish standard methods of cheese making whereby 

 the milk can be brought into uniform condition from day to day, and 

 thus to make it possible to manufacture a uniform article. 



The bacteriological work in connection with this line of investiga- 

 tion has been a continuation of the study of the forms of bacteria 

 important in the manufacture of Cheddar cheese. Specific cultures 

 have been isolated from cheese made of raw and of pasteurized milk, 

 and these cultures have been studied, considerable attention being 

 given to the high-acid-producing bacteria found in cheese. Chejnical 

 work to a considerable extent has been devoted to the nonnitrogenous 

 constituents of good and poor cheese at different stages in ripening. 



Soft cheese. — The work on the Roquefort variety of cheese has 

 comprised the investigation of (1) the chemical composition of 

 Roquefort cheese and the establishment of a standard for this variety 

 as compared with other varieties; (2) the chemical changes taking 

 place in the process of ripening; (3) the effect of salt on the ripening 

 process; (4) the method of handling the ]io(|uefort mold powder used 

 in inoculating the cheese; (5) the ellect of lactic-acid starters in manu- 

 facturing this variety ; (6) the water content and its relation to the 

 proper ripening of the cheese. 



Chemical work in connection with these investigations was devoted 

 to an investigation of the water content at various stages of ripening, 

 the means of controUing it, the relation of acid in the milk to the qual- 

 ity of the cheese, and methods of salting and handling the cheese dur- 

 ing the process of ripening. 



There are various minor problems under investigation in connection 

 wnth the work on soft cheese. These investigations develop results 

 rather slowly, because there has been so little experimental work done 

 along this line and because there are so many questions that demand 

 study. This work is being conducted in a thorough and comprehen- 

 sive manner, and this requires much time and work. However, one 

 by one the questions involved are becoming understood, and it is 

 hoped that in time this work will supply knowledge that will serve 

 as a basis upon which a profitable soft-cheese industry may be estab- 

 lished in America. 



