106 



GRADING AND TESTING MILK AND CREAM 



is being used when the fat column is golden yellow to light amber 

 in color. 



2. Mix contents of bottle thoroughly. 



3. Centrifuge for six minutes. 



4. Add hot water (soft or distilled) to fill bottle to bottom 

 of neck, and whirl for two minutes. 



5. Add balance of water to float fat into neck and again whirl 

 for two minutes. 



6. Read at temperature of 130 to 140 F. Double the read- 

 ing to obtain per cent of fat. 



7. In cleaning test bottle especially if there be any deposit- 

 first add a small amount of lukewarm water and to this add 

 sulphuric acid. Always add the water first and then the <acid 

 never the reverse. Rinse the bottle well with this mixture and 

 then rinse with hot water. 



This test gives results corresponding to those of chemical 

 analysis. 



A test bottle, with a scale reading up to .50 per cent for 18 

 grams, should be used. 



The following table, comparing the Babcock, The American 

 Association Test, and Rose-Gottlieb (Chemical) tests, is sub- 

 mitted. 



1 The Babcock test given in the foregoing table was that obtained from using 

 12 c.c. of sulphuric acid with a g-gram sample and centrifuging, in all, about 

 thirty-five .ninutes in a high-speed tester. 



