372 CHEESE 



are carried further and at a more rapid rate, complete 

 ripening occupying not more than three or four weeks, 

 instead of as many months. 



In normal examples tryptophane, indole, skatole, sul- 

 phuretted hydrogen, and other products of putrefactive 

 fermentations are absent. 



Good Camembert cheese contains about .25 per cent. 

 of ammonia when ripe, mainly combined with acid 

 radicles ; only in over-ripe samples can free ammonia be 

 detected, its occurrence in considerable amounts indicating 

 putrefaction and decay. 



The biological factors in the ripening of soft cheeses 

 are different from those of the hard varieties ; in the 

 latter, bacteria alone are mainly responsible for the 

 chemical changes, while the former are ripened chiefly 

 by means of fungi. 



In both types, of course, the lactic acid organisms are 

 abundant, and assist in the preliminary changes occurring 

 in the cheeses ; but in the soft Camembert cheese Penicil- 

 lium candidum, Rogers (by some authors named Penicillium 

 Camembertii} is the active ripening agent, the mycelium 

 of this fungus secreting a proteolytic enzyme which 

 diffuses into and peptonizes the acid curd. 



Always associated with it is Oospora lactis and various 

 yeasts, to which the pleasing aroma and flavour are in 

 part due, for cheeses ripened with pure cultures of P. 

 Camembertii do not develop the characteristic Camembert 

 taste. 



For a successful result an abundant development of 

 Streptococcus lacticus and allied lactic organisms is 

 essential, otherwise foul-smelling decompositions are 

 certain to arise. 



In three or four days the two fungi just mentioned 



