DAIRY HUSBANDRY 
23 
EXERCISE NO. 15 
Object: To become acquainted with the principal of standardizing milk and 
cream. 
Procedure: The legal standard for fat in cream is 18% in the United 
States. It is permissible to reduce the test of rich cream to a 
minimum of 18% by the addition of a milk product. This 
process is known as standardizing. Standardizing milk or 
cream means the adjustment of the fat or solids content to a 
certain desired percentage. This is accomplished by the mix¬ 
ing in the proper proportion of two qualities of milk or cream, 
one higher, and the other lower than the desired standard. 
A. Make a test of two lots of milk provided. (One to contain 
over 5% fat and one less.) Record the tests. 
B. By using the Pearson square method calculate the porportion 
of each lot of milk required to make a 5% mixture. 
Tests of originals 
Square 
Proportion of each 
Amt. of each 
. 
The proportion of each is derived by subtracting diagonally 
across the square using the desired standard either as the sub¬ 
trahend or minuend as the case may be. The smaller number 
is always subtracted arithmetically from the larger. 
C. Calculate the amount of each lot necessary to prepare exactly 
100 cc. of a mixture testing 5% fat. 
D. Make an accurate test of the prepared mixture. 
Observations: 
Sample 
Test 
Proportion 
cc. of each 
1 
a 
b 
2 
a 
1) 
3 
a 
b 
