164 SCIENCE AND PRACTICE OF CIIEESE-MAKING 



lytical data are given later on p. 168. Under these 

 conditions, the pasture grasses were badly burned, 

 most of the dairymen were without supplementary 

 supplies of food, and consequently the cows suf- 

 fered a certain degree of starvation. The changes 

 in composition of milk were accompanied by a 

 severe shrinkage in yield of milk. Along with this 

 impaired condition of food supply, the animals 

 were subjected to the unfavorable effects coming 

 from excessive heat combined with annoyance of 

 flies. Cheese-makers often complain of the be- 

 havior of the cheese made at such times, without 

 understanding the cause of their difficulty. The 

 cheese leaks fat badly, does not press together well, 

 and does not stand up perfectly, although behaving 

 properly when first made. There is also noticed 

 an excessive loss of fat in whey. This behavior is 

 due to an abnormal decrease of casein in relation 

 to fat, so that the milk and cheese contain an ex- 

 cess of fat. Cheese-makers at such times are really 

 dealing with milk which is not normal factory milk, 

 but which is like normal factory milk to which some 

 cream has been added. The extreme heat of the 

 weather, which causes the decrease of casein, also 

 makes it more difficult to handle such milk in cheese- 

 making. In the twelfth annual report of the Wiscon- 

 sin experiment station, attention is called to a similar 

 condition. 



RELATION OF FAT AND CASEIN IN MILK 



As we shall see later (p. 231), the relation of 

 fat and casein in milk is an extremely important 

 one in connection with cheese-making. At this 



