SOFT CHEESES. 



20 5 



The ripening occupies from five to eight weeks, and a series of 

 changes takes place in the cheese, of which the following is a 

 summary: 



The first phenomenon that occurs is the souring of the curd, 

 which is brought about by the Bact. lactic acid type of organism. 

 These bacteria grow in the milk previous to the addition of the 

 rennet, although the milk is not allowed to become very sour before 

 curdling. But they continue to grow during the curdling and for a 

 day or two after the cheese is made. If by 

 any chance the lactic bacteria fail to develop 

 vigorously, a ruined cheese is sure to result. 



The second step in the ripening is the ap- 

 pearance on the surface of the cheese of a 

 species of mold, which has been named 

 Penicillium camemberti (Fig. 44). This mold 

 appears in from two to four days and is at first 

 of a pure white color; later, when it begins to 

 produce spores, it becomes a steel gray, but 

 never a deep blue like the common mold. It 

 is a species of mold that apparently does not 

 occur in America, but is very common in 

 Europe in those sections where Camembert 

 cheese is made. Its absence from America is 

 the chief reason why this country has been unable to make 

 Camembert cheese. Where successful cheese of this type has been 

 produced, it has been by importing and inoculating this type of 

 mold into the American cheese factories. This white mold grows on 

 the surface of the cheese, but does not penetrate below the surface. 

 After about two weeks it reaches its limit of growth, forms spores, 

 and dries down to a somewhat thin crust. The growth of this mold, 

 together with other organisms, neutralizes the acid of the curd at 

 the surface of the cheese and renders it slightly alkaline. 



In the meantime the mold has secreted an enzyme which has 

 the power of digesting the curd. As fast as the acidity of the curd 

 is reduced and the enzyme secreted, the latter acts upon the curd, 

 changing it from a hard consistency to a soft texture. At first the 



FIG. 44. Penicillium 

 camembertii, the mold 

 ripening camembert 

 cheese (Thorn). 



