234 BACTERIA IN CHEESE MAKING. 



peculiar effects that take place in the cheese. Some of the 

 cheeses are made from whole milk ; some of them from part 

 whole milk and part skim milk; some from milk of sheep 

 or goats ; some of them are salted, and some not salted ; some 

 are partly deprived of .water by draining, while in other cases 

 the curd is simply ladled out of the curdled milk; some are 

 ripened at moderately high temperature, some at low tem- 

 perature, and some are ripened for a while at one temperature 

 and later at a different temperature, and so on. The methods 

 that are devised vary as widely as the different types of 

 cheese. In general the soft curd, without very much drain- 

 ing, is taken from the curdling vat and placed in forms for 

 shaping. These forms, being used over and over again, 

 become thoroughly impregnated with the spores of molds, 

 and the cheeses, while they are shaping in the forms, are at 

 the same time inoculated with the molds. After they have 

 assumed a proper consistency they are then commonly placed 

 in ripening rooms. Here the molds grow luxuriantly over 

 the cheese and in time cover it perhaps completely. The 

 growth is allowed to continue for a time, determined by 

 experience, and then the cheeses are frequently placed in a 

 second ripening room where the temperature and other con- 

 ditions are such as to check the growth of molds and encour- 

 age the development of bacteria. Now a new series of 

 changes takes place, due to the development of bacteria. 



The details of the ripening of the different kinds of cheeses 

 are hardly understood in any single case. The ripening of 

 the Roquefort cheese is perhaps as fully comprehended as 

 any; but here, although we are familiar with the fact that 

 molds are the chief agents in producing the flavors, 

 we are quite in ignorance of the chemical changes which 

 are produced. Camembert cheese is ripened by two bacilli 

 (263), one a lactic species which at first grows only in the 

 center of the cheese, and the second a peptonizing species 

 which grows at the outside, gradually extending towards the 



