CREAMERY BUTTER MAKING 37 



3.9^ fat 



2.9/fc casein 



0.5^ albumen 



4.9* sugar f = 9-*= solids not fat. 



0.7^ ash 



Total I2.9^=total solids. 



Relationship of Fat and Solids not Fat. In normal 

 milk a fairly definite relationship exists between the fat 

 and the solids not fat. For example, milk rich in fat is 

 likewise rich in solids not fat. On the other hand, milk 

 poor in fat is also poor in solids not fat. As a general 

 rule, an increase in the solids not fat always accompanies 

 an increase in the percentage of fat. The increase is, 

 however, not quite proportionate, the fat increasing the 

 more rapidly. 



Since the casein represents the most valuable constitu- 

 ent of the solids not fat, the following ratio between this 

 substance and the fat very well illustrates the relation- 

 ship that exists between the fat and solids not fat in milk : 



According to Van Slyke. 



Per cent fat. Per cent casein. 



3.00 2.10 



3.25 2.20 



3-'50 2.30 



3-75 2.40 



4 . oo 2 . 50 



4.25 2.60 



4.50 2.70 



Specific Gravity as Affected by Richness of Milk. 



The richness of milk seems to have but a very slight 

 effect on its specific gravity. Usually a four per cent 

 milk shows a slightly higher reading than a three per 



