TESTING 249 



carry it down into the acid solution. The amount of water 

 necessary to dilute the cream depends on the percentage 

 of fat in the cream, and on the method usually followed 

 by an operator. Often a creamery operator will add 

 approximately 9 c.c. of water to 9 grams of cream. Many 

 creamery-men do not add water; thus less acid is 

 necessary, which is a saving of expense and time. Or- 

 dinarily at least a few cubic centimeters of water should 

 be put into the cre#m. 



4. Add the sulfuric acid. The amount necessary 

 depends largely on the quantity of water used in step 3, 

 and on the temperatures of the cream and acid. Usually 

 9 grams of cream and 9 c.c. of water require about 2 

 or 3 c.c. less acid than whole milk, or 14 or 16 c.c. 

 If no water is added, approximately 8 c.c. of acid is 

 sufficient. There should be enough acid added to bring 

 the color of the solution and cream to a chocolate 

 brown shade. 



Steps 5, 6, 7, 8, 9, and 10 are the same as steps 4, 5, 6, 

 7, 8, and 9, under " Testing whole milk," par. 222. 



5. Place the test-bottles in a specially constructed 

 tank or bath for maintaining uniform temperatures, after 

 the water in the bath has first been regulated to the 

 proper heat. According to Hunziker, 1 the temperature of 

 the fat when read should be 135 F. Ross and Mclnerney 2 

 state that the temperature of the fat at this time should be 

 between 140 and 150 F. for at least three minutes. This 

 means that the tempering water should be raised as high 

 as the top of the fat column in the test-bottles and that 



1 Hunziker, O. F., Testing Cream for Butter Fat, Purdue 

 Univ. Agri. Exp. Sta., Bui. 145, p. 591, 1910. 



2 Ross, H. E., and Mclnerney, T. J., The Babcock Test with 

 Special Reference to Testing Cream, Cornell University Agri. 

 Exp. Sta., Bui. 337, p. 41, 1913. 



