No. 6. DEPARTMENT OF AGRICULTURE. 605 



CHAPTER VII. 



PRELIMINARIES OF CHEESE-MAKING. 



As compared with butter-making, the process of cheese-making 

 is much more complicated in its details and difficult to control. 

 It is probably true that our best methods of butter-making are 

 much nearer perfection than are our best methods of cheese-making, 

 but many improvements have taken place in the details of the pro- 

 cess of cheese-making during the past twelve or fifteen years. Be- 

 fore the actual operation of cheese-making begins, there are several 

 details which can properly be considered in a separate chapter. We 

 shall, therefore, discuss in this chapter (1) the care of milk by the 

 dairyman for cheese-making, (2) the method of testing milk to detect 

 injurious forms of fermentations, (3) the action of rennet in cheese- 

 making, and (4) the ripening of milk for cheese-making. 



47. Care of Milk for Cheese-Makiog. 



In section 13, p. 570, we discussed in considerable detail the pre- 

 cautions to be observed in securing clean milk when the milk is to 

 be sold for direct consumption. All the precautions given there 

 in regard to the conditions of cleanliness to be observed apply with 

 equal force to milk that is to be used for cheese-making. However, 

 in the case of milk intended for cheese-making, after it has been 

 drawn, removed from the stable and strained, we do not need to be 

 so careful in keeping the lactic acid bacteria from growing as we 

 do with milk to be sold for direct consumption. While most of the 

 undesirable forms of fermentation, commonly occurring in milk, may 

 work injury in cheese-making, it is, so far as we now know, very 

 necessary to have more or less lactic acid fermentation in the milk 

 and curd during the cheese-making process, in order to make good 

 cheese, especially in the case of our common type of cheese, the 

 American cheddar. There are two additional points to which special 

 attention will now be called in caring for milk for cheese-makiog and 

 these are (1) cooling and (2) aerating. 



(1.) Cooling Milk. — It is desirable to cool the milk down to the 

 temperature of the surrounding air, or, still better, to 60 degrees F., 

 if it has to be kept long. It is a good plan to assist the cooling 

 by constant stirring. Two objects are thus accomplished. In the 

 first place, in milk thus treated the fat tends to cream less rapidly, 



