SOFT CHEESES. 203 



Rusty Spot. This is characterized by rusty, red spots on the 

 outside and, indeed, not infrequently throughout the whole cheese. 

 The cheese loses its value and may in the end become quite ruined 

 if the trouble develops sufficiently. The cause is a bacterium, B. 

 rudensis. 



Many other "faults" may be recognized as interfering with the 

 normal ripening. Black spots and blue spots are sometimes noticed 

 and a variety of "off" flavors that cannot be described. In regard 

 to all of these troubles the cheese-maker has the serious disad- 

 vantage that they cannot be discovered until the ripening has be- 

 come partially completed, and then it is too late to apply any 

 remedy. The method of meeting them must be by prevention 

 rather than cure, and after an improper ripening has begun, practi- 

 cally nothing can be done to stop it. By cleanliness, by frequent 

 sterilization of vats, and by the use of vigorous lactic acid starters 

 much can be done to prevent these troubles, but there seems to be 

 no remedy after the improper ripening has begun. A vigorous 

 lactic acid starter will go far toward preventing gassy cheese, and 

 the slimy whey used in the Edam cheese prevents it in that particular 

 brand. A regulation of temperature during ripening will also aid, 

 since the gassy organisms grow best at higher temperatures, while at 

 a lower, about 60, the common lactic acid bacteria are the more 

 vigorous. When to these two suggestions of vigorous starters and 

 cool temperatures we add great care in keeping all milk-vessels clean, 

 and in sterilizing frequently by steam, we have included practically 

 the only methods in use of much significance in guarding against 

 the various cheese faults. 



SOFT CHEESES. 



The essential difference between a hard cheese and a soft cheese 

 is that the latter has a very much higher percentage of moisture. 

 To bring about this condition, the method of manufacture is de- 

 signed to retain the whey in the curd. After the milk is curdled the 

 curd is sometimes dipped out directly into forms provided with 

 holes in their sides, through which the whey drains naturally 



