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LABORATORY MANUAL 
SERIES I. 
Testing Cheese. 
Materials necessary for 10 students: 
5— 5 gram weights. 
5—9 or 10 gram weights. 
5—2 gram weights. 
*10—small tin evaporating dishes. 
1—High pressure oven. 
EXERCISE NO. 43 
Object: To determine the fat content of cheese by using the Babcock test. 
Procedure: “It is important in testing cheese, just as in other dairy prod¬ 
ucts that a correct sample be obtained. This is done as follows: 
Draw a plug from a sound portion of the cheese with a cheese 
trier; this should be taken at a point that is not near the rind, 
a cut surface of the cheese, a defective spot or an old trier hole. 
Cut off the top one-half inch of the trier plug and replace it 
in the trier hole to protect the cheese.” (F. & W. f 105.) 
A. Carefully weigh 9 or 10 grams of cheese into a 30% cream 
test bottle. The more finely divided the cheese when placed 
in the test bottle, the easier it will be to get the cheese into solu¬ 
tion. Add from 10-15 cc. of hot water and allow the cheese to 
emulsify. Hold the bottle in a hot water bath to complete the 
emulsification if necessary. The addition of 2-3 cc. of sulfuric 
acid, and vigorous shaking from time to time will also aid in 
the emulsification. 11 is important, in order that satisfactory 
results be obtained, to have all cheese emulsified. When no 
more lumps are seen in the liquid add 17.5 cc. of sulfuric acid, 
and complete the test in the usual manner. 
B. Whirl in centrifuge as for milk. 
C. Read as for cream, and calculate the test by using the formula: 
Reading X18 
-= % fat. 
grams used 
Note: Add acid in small quantities as a large quantity at one 
time causes too intense action. Carefully wash down all 
cheese particles from the neck of the bottle before adding 
the acid. 
Observations: 
Sample 
Grams cheese 
Reading 
% fat 
Condition 
Color 
1 
2 
Conclusion: 
