Relation of Bacteria to Cheese. 79 



mark of this type of cheese. They are of commercial 

 value since a cheese that lacks them will not sell for as 

 much as one of similar flavor and texture containing the 

 eyes. At the time when the cheese is supposed to be at 

 its best, the eyes often contain a clear brine which is 

 termed "tears." The eyes are caused by bacteria that 

 change a portion of the lactic acid to propionic and 

 acetic acids. Carbon dioxide is also produced. This 

 gas produces the holes. The change of the lactic acid to 

 other acids undoubtedly influences the flavor of the 

 cheese. 



Roquefort, Gorgonzola, and Stilton cheese. There 

 are three kinds of cheese found in the world's markets 

 that are very peculiar as to the manner of ripening. 

 These cheese are Roquefort, Gorgonzola and Stilton. 

 The first is made in France from sheep 's milk, the others 

 are made from cows' milk. These cheese are luxuries, 

 selling for fifty to seventy -five cents a pound. 



The rennet and lactic acid bacteria play the same role 

 in the manufacture and ripening of these cheese as in 

 the cheddar cheese. One of the causes of the peculiar 

 flavor of these cheese is a mold very similar to the ordi- 

 nary blue-green bread mold. In the making of Roque- 

 fort cheese, the curd when put to press is sprinkled with 

 bread crumbs upon which the mold is growing. This 

 mold like all others can grow only in the air, and in order 

 to allow the air to penetrate into the cheese, it is pierced 

 full of small holes by means of slender needles. The 

 mold grows and forms its greenish spores, giving to the 

 -cheese, when cut, the appearance of green and white 

 marble. The flavor is characteristic and is produced 

 only when the mold is present. 



Gorgonzola and Stilton cheese contain the same mold 



