150 MILK [ix 



in which the milk has been coagulated. This deter- 

 mines, to a certain extent, the composition of the 

 curd, its physical condition, such as its fineness. 

 Among other conditions are the degree of moisture 

 in the curd, the percentage of fat, the regulation of the 

 temperature during the numerous processes, and the 

 sourness of the curd. One point of enormous import- 

 ance in cheese-making is to obtain a similarity of 

 composition in the curd. 



Bacteria in Cheese That the ripening of cheese 

 is due to the action of micro-organisms has been 

 conclusively proved. Thus, for example, if means be 

 taken to prevent the growth of bacteria, by subjecting 

 the cheese, as has been done, to a stream of carbonic 

 acid gas, or if cheese be made from sterilised cream, 

 it is found that no ripening takes place. Similar 

 results have been obtained by treating the cheese 

 with some disinfecting agent, which would prevent 

 bacterial growth in the cheese without affecting its 

 chemical condition. As to the nature of these 

 organisms, however, and as to the specific functions 

 they exercise, much doubt yet remains. Different 

 investigators have attempted to estimate their 

 number. Thus Adametz found, in a gramme of fresh 

 cheese, from 90,000 to 140,000, and Freudenreich as 

 many as 1,800,000. The former observer has found 

 850,000 in a gramme of Swiss cheese, and in the 

 same amount, taken from the outer layer, of soft 



