CHEMICAL TKSTS AND ANALYSES 



351 



Butter Fat. 



The Babcock Test. 



Standard Glassware. 1 



(a) Standard milk test bottles, graduated to 8 per cent and 

 with sub-divisions of .1 per cent. 



(b) Standard pipette graduated to 17.6 c.c. 



(c) Acid measure graduated to 17.5 c.c. 



(d) Centrifuge-Babcock tester. 



(e) Water bath for reading at 130 to 140 degrees F. 



(f) Calipers for measuring fat column. 



(g) Sulphuric acid, specific gravity 1.82 to 1.83. 



Determination. 



Pipette 17.6 c.c. of the properly mixed sample of milk into 

 the milk test bottle. Add 17.5 c.c. of acid and shake until all the 

 curd is completely dissolved. 

 Both milk and acid should have 

 a temperature of 55 to 70 de- 

 grees F. If milk and acid are 

 too warm, set the sample bot- 

 tles and the acid jar into a 

 trough or tub of water at 55 to 

 70 degrees F. for thirty minutes 

 before testing. The test bottles 

 containing the mixture of milk 

 and acid are then whirled in 

 the Babcock tester for five 

 minutes at about one thousand 

 revolutions per minute, in the 

 case of a tester with a twelve- 

 inch diameter wheel. Fill the 

 test bottles to the bottom of 

 the neck with hot water. The 

 water should be soft, preferably rain water or distilled water. 

 If hard tap water is used it should be boiled to precipitate the 

 carbonates, otherwise the test may be difficult to read, owing to 

 the presence of bubbles of gas on top of the fat column. Revolve 



Fig'. 110. Babcock tester 



Courtesy of Creamery Package Mfg. 

 Company 



1914. 



Hunziker, Indiana Agricultural Experiment Station, Circulars 41 and 42, 



