CHEESE 619 



taste of Roquefort cheese is caused by the formation of hydro- 

 lyzable salts of caproic, caprylic, and capric acids. Penicillium 

 roquefortii produces a water-soluble lipase which decomposes the 

 fat, with the formation of the acids mentioned. 



The initial stage of cheese ripening is more or less alike in all 

 cheeses. There is always acid present and peptonization com- 

 mences early. There are some differences even in early stages. 

 For example, in Emmenthaler cheese a large quantity of acid is 

 not desirable, although the use of cultures of lactic acid bacteria 

 is quite general, while in Cheddar cheese the presence of much 

 acid is of importance. After the first stage of ripening, processes 

 begin to differ materially in the many types of cheese. All 

 manipulations are calculated to favor the development of the 

 kind of micro-organism which produces the particular type of 

 cheese. Cheddar cheese is ripened at low temperature; for Em- 

 menthaler cheese the curd is heated; salt is worked in with the 

 curd in Cheddar cheese ; in Emmenthaler no salt is added at first, 

 but is placed on the outside from time to time. That these and 

 other methods of treating cheeses are important for microbial life 

 is a matter of recent understanding, but one long experienced. 

 However, since it has been understood that micro-organisms are 

 the chief agencies in cheese ripening the reasons for different 

 manipulations have become apparent. With the aid of the re- 

 sults of scientific investigations conditions can be regulated with 

 more precision that heretofore. 



Emmenthaler cheese is not perfect without holes, commonly 

 called "eyes." The formation of these holes occurs at relatively 

 high temperature. After a period of ripening at low temperature 

 the cheese is placed in a room with a higher temperature to favor 

 hole formation. In Cheddar cheese holes should not form, and, 

 therefore, it is ripened at low temperature to the end of the process. 



In the presence of much acid, peptonization proceeds rather 

 slowly, but during later stages of ripening, when the acid is neu- 

 tralized in whole or in part by the activity of molds and bacteria, 

 peptonization is more rapid. When the fresh curd contains but 

 a small amount of acid there is usually a secondary acid fermenta- 

 tion later. 



Cottage cheese and buttermilk cheese are simple to prepare 

 and require little if any ripening. Cottage cheese is usually made 

 from skimmed milk and is a nourishing, palatable food, especially 

 when sweet or sour cream is mixed with it. One gallon of skimmed 

 milk furnishes about If pounds of cottage cheese. According to 

 Matheson and Cammack, cottage cheese can be prepared as fol- 

 lows: Sweet skimmed milk is set aside at a temperature of about 

 75 F., and after it has coagulated, which process takes about 



