ACID TESTS “89 
cream it is distributed through only 65 pounds of serum, 
hence the latter must have the greater intensity of acidity. 
This may be graphically shown as follows: 
Poor cream. Rich cream. 
25% fat. 35% fat. 
75% serum. 65% serum. 
.5% acid. i acid. 
In the illustrations above it is seen that the acid in the 
rich cream is distributed through less space than in the 
poor, hence the degree of acidity must be higher in the 
rich cream. 
We find in practice where the same results are to be 
expected from the ripening process, a 25% cream must 
show about .6% acidity, while a 35% cream, about .5%. 
In bulletin No. 24 of the Washington Experiment Sta- 
tion, Prof. Spillman gives a table showing the required 
acidity for cream of different richness. 
