DAIRY PRODUCTS 379 



EXERCISES 



1. The Babcock test. 1 The apparatus consists of a i7.6-cubic- 

 centimeter acid-measure pipette, test bottles, dividers, water bath, cen- 

 trifuge, and sulphuric acid with a specific gravity of 1.83 to 1.84. 



Full directions for the use of the Babcock testing outfit are fur- 

 nished by the manufacturers or may be secured from the state 

 agricultural college. Samples of milk should be secured, and the 

 whole amount produced by each cow being tested should be carefully 

 weighed on three successive days. The butter fat in the milk should 

 be determined by use of the Babcock tester according to the direc- 

 tions furnished. Compute the amount of butter fat produced during 

 the month by each cow tested. By adding one fifth to the amount of 

 butter fat, the amount of butter produced is determined. 



2. Methods of milking. Obtain two pails one with open top, the 

 other with a partially closed top. Milk one half the milk from the cow 

 into each pail. Pour a sample of the milk from each into two bottles 

 and note which one keeps sweet longer. 



3. Methods of keeping milk. Take two samples of milk fresh from 

 the cow, cool one immediately to 50 degrees or lower (do not cool the 

 second sample), place both samples in a fairly cool place (65 degrees F.), 

 and note how long it takes each sample to sour. 



4. Methods of creaming. Thoroughly mix a can of warm milk 

 (90 degrees F.). Pour one fourth of it into a shallow pan, another 

 fourth into a deep can, and another fourth into a second deep can. 

 To the second deep can add as much water at a temperature of 

 50 degrees as there is milk. Set the pan and the two cans in cold 

 water, and note the time required for the butter-fat globules. to rise 

 and form cream. Test the skim milk and the cream in each case and 

 compare results. 



5. Richness of milk on creaming. Get a sample of milk from a 

 rich-testing cow and also a sample from a low-testing cow. Bring 

 both samples to 90 degrees F. and run them through the centrifugal 

 separator. Test the cream and skim milk from both samples and 

 compare the results. 



6. How rapidly to turn the separator. Divide a thoroughly mixed 

 can of milk into three equal parts. Run one part through the 



1 Standard Babcock milk testers are now sold by many dealers and may be 

 secured by a local merchant. 



