DAIRYING 139 



casein it contained, irrespective of the 

 fat. 



However, it is now being gradually accepted 

 that the fat is of nearly equal importance 

 with the casein. Hence the richer the milk 

 is in fat, the more cheese it will make. As 

 the result of numerous experiments, carried 

 out by Dr Van Slyke, it has been proved that 

 the percentage of casein increases in propor- 

 tion to the increase of fat, up to a certain 

 point (about 4.5% fat). 



Casein in milk exists in a semi-dissolved or 

 colloidal form. 



The object of the cheesemaker is to Rennet 

 change it from the soluble to the insoluble 

 or coagulated form. During the process of 

 coagulation, the casein entangles the fat in 

 its mass. The coagulation of the casein 

 may be effected by different re-agents, but 

 the one usually employed is rennet, which is 

 a secretion of the glands of the fourth or 

 digestive stomach of the calf. It must be 

 obtained from an animal at least a week old, 



