436 MICROBIOLOGY OF MILK AND MILK PRODUCTS 



forming bacteria is similar, if not identical, to their r61e in Cheddar 

 cheese, i.e., in activating the pepsin of the rennet and in preventing 

 the growth of putrefactive bacteria. The factors concerned in flavor 

 development are different. 



RoQUEPORT Cheese. — This cheese, which is prepared almost 

 exclusively in the Department of Aveyron in southern France, is made, 

 from sheep's milk. Its most striking characteristic is the marbled 

 or mottled appearance of the interior, due to the growth of a mold, 

 Penicillium. roqueforti, Thom. The curd is inoculated with the mold, 

 when it is placed in the press, by sprinkling the curd with bread crumbs 

 on which the mold has grown. The growth and sporulation of the 

 mold in the interior of the cheese are favored by piercing it with 

 small needles, thus admitting air. The characteristic flavor is due, 

 partially at least, to the mold. 



This cheese is cured in c^es having a temperature below 15°. 

 The fermentative processes are apparently closely dependent on the 

 moisture and temperature conditions of the curing room. This 

 emphasizes the importance of biological factors in the ripening process. 



GoRGONZOLA CHEESE, prepared in Italy from cow's milk, and 

 Stilton cheese, made in England are similar to Roquefort in 

 appearance and contain the same mold — Penicillium roqueforti. 



Camembert Cheese. — The soft cheeses are best represented by 

 this important French cheese made from cow's milk by the addition 

 of rennet. The milk is ripened to an acidity of 0.20 to 0.25 per cent 

 before the addition of the rennet. The curd, which thus contains 

 many acid-forming' bacteria, is neither cut nor heated in order to re- 

 tain the maximum amount of whey. The curd is placed in small 

 hoops and allowed to drain without pressure. Salt is applied to the 

 surface of the cheese. 



The milk sugar is rapidly fermented and the resulting acidity 

 is high, for the cheese contains 60 to 70 per cent of moisture when 

 fresh and 50 per cent when ready for consumption. The high moistiure 

 content of the cheese and the humidity and temperature conditions 

 of the curing room favor the rapid development of microorganisms 

 on the surface of the cheese. Both molds and bacteria thrive under 

 the influence of these favorable conditions, changing the cheese to 

 a soft, smooth and butter-like mass, while a characteristic flavor is 

 developed. 



