DAIRY HUSBANDRY 
57 
EXERCISE NO. 42 
Object: To become acquainted with the ether extraction method of fat 
determination of butter. 
Note: High test gasoline may be substituted for ether. 
Procedure: “Attempts have been made to use the Babcock glassware 
and tester for the determination of fat in butter, but the results 
have not been entirely satisfactory, and only a fair degree of 
accuracy may be expected.” (F. & W. 1 102-103.) 
A. Determine the moisture content of a sample of butter as out¬ 
lined in Exercise 40. Use a rather narrow lipped aluminum 
beaker having a capacity of about 100 cc. 
B. After the breaker is weighed to determine the loss in moisture, 
fill with petroleum ether and stir with a glass rod. Cover with 
a watch crystal and allow to stand for 2 or 3 minutes to allow 
the curd and salt to settle. Decant off the solvent without 
disturbing the sediment. Fill with petroleum ether again and 
stir. Allow to settle. Decant off after a short time. 
Best results will be obtained if both the ether or gasoline and 
fat are warm. 
C. Heat the beaker gently over hot plate, or water bath to 
drive off ether. Avoid sputtering due to overheating. 
D. Reweigh the beaker and determine the per cent fat by the dif¬ 
ference in weight. 
E. Determine the salt content of the residue as in Exercise 41. 
Note: The result for the curd will be slightly low and that 
for fat high due to a slight loss (about .2 per cent) in decanting 
off the ether fat mixture. 
Observations: 
Sample 
Weight 
Weight of water 
% water 
Weight of fat 
% fat 
1 
2 
Conclusions: 
Questions: (1) What is the average composition of American butter? 
(2) What is the legal standard for butter in each of the four leading 
foreign butter producing countries? 
(3) Name the five leading butter producing states in the U. S., and 
give the amount each produces. m 
(4) Name the four leading butter producing nations. 
References: F. & W., p. 307; Van S. p. 16. 
