232 



BACTERIA IN CHEESE MAKING. 



necessary, and to furnish oxygen the cheese is sometimes 

 pricked full of holes by a special machine provided with 

 large numbers of fine needles. This allows air to enter and, 

 when the cheese is placed at a proper temperature, the molds, 

 which are thus brought in condition for growth, develop rap- 

 idly and in time the .whole cheese becomes filled with them. 

 The development of the molds gives presently the peculiar 

 taste to the Roquefort cheese. We thus have here an ex- 

 ample where the flavor of the product is due primarily to 

 the growth of molds. A somewhat similar process is 

 adopted in the manufacture of the Stilton cheese (Fig. 29), 

 although details of the preparation are slightly different. 

 Within recent years a common Danish cheese, known as 

 Gammelost, has been found to be ripened by the growth of 

 molds (285). Two or three species have been separated 



FIG. 30. 



Molds concerned in ripening of Gammelost cheese. (Johan-Olsen.) 



from this cheese (Fig. 30). They have been cultivated by 

 laboratory methods and used for artificially inoculating 

 cheeses, with the result that a high quality of a marketable 

 product has been produced, thus making it evident that here 

 is a third type of cheese, the essential nature of which is 



