248 THE BOOK OF BUTTER 



whereas in other factories the record keeping would be 

 even more simple if the composite method were in force. 



224. Testing cream. The testing of cream for fat 

 by the Babcock method is similar to that of testing milk. 

 Some of the steps require modification. The procedure 

 should be as follows: 



1. Agitate the sample thoroughly in order to obtain 

 an aliquot portion to test. If the cream is cold, it should 

 be warmed to 80 or 85 F. 



2. Weigh 9 grams of the cream into the test-bottle. 

 The bottle that is now in common use is graduated to read 

 to 50 per cent and the reading is obtained directly if 9 

 grams of cream are used. It is necessary to have delicate 

 scales and they must be maintained in a sensitive con- 

 dition. Only one bottle should be weighed at a time. 

 Many creameries use scales that weigh as high as twelve 

 bottles at once. Scales that carry so many bottles are 

 not as delicate as the smaller ones, and there is greater 

 opportunity for error when several bottles are balanced 

 at one time. The purposes of weighing instead of measur- 

 ing cream as practiced with milk are : (a) cream is so 

 sticky that it cannot all be discharged from the pipette ; 

 (b) the specific gravity is variable, for it may test 15 or 

 16 per cent or may contain 60 per cent fat or more ; (c) 

 cream contains variable quantities of air. Therefore, 

 all cream samples should be weighed. They should never 

 be measured. 



3. Add cold or warm water or do not add any, depending 

 on conditions and the results of experience. If the cen- 

 trifuge becomes very warm on account of poor exhaust 

 of steam, or in very warm weather, cold water may be 

 used. Ordinarily the water should be sufficiently warm 

 to melt the fat in the neck of the cream test-bottle so as to 



