A DAIRY LABORATORY GUIDE 55 



EXERCISE IX 



BABCOCK TEST. LACTOMETER READING 

 AND ACID TEST 



1. Make a Babcock test of cheese, whole milk and 



skimmed milk. Add acid to the skimmed 

 milk about one-quarter of an inch above the 

 usual mark, and run ten minutes, two min- 

 utes and one minute. 

 Run the whole milk the usual time at the usual 

 speed. Be sure to cut the cheese fine before 

 putting into the test bottle. 



2. (a) Retest the whole milk, running the machine 



one minute, one minute, one minute. Do 

 you get any different results either in the 

 amount or the appearance of fat? If so, 

 give the reasons. 

 (b) Retest the whole milk, running the machine 

 fifteen minutes, five minutes and three 

 minutes. Do you get any more fat than 

 when the machine is run the usual length 

 of time? 

 Oil the machine well before each run. 



3. Take the B. of H. lactometer reading of 



skimmed milk and whole milk. Make correc- 

 tions for temperature and figure out the 

 S. N. F. and T. S. For whole milk use three 

 formulae. 



4. Test the whole milk for acid, using i8 grams. 



Use both n/io and alkali tablet solution. 

 Test the skimmed milk for acid, with the n/io 

 solution. Use only 5 cc. of the milk, so that 

 one result will be a check on the other. 



