634 TESTING BUTTER 



When done using the thermometer, scrape it off on one side of 

 cup, but do not wipe it off, so as to avoid removing fat from the test, 

 and getting the next test too high. 



Second Weighing: Weigh cup again and calculate the per 

 cent moisture by deducting the second weighing from the first weigh- 

 ing, dividing the difference by the net weight of the sample (first 

 weighing) and multiplying the result by 100. 



Example : 



Butter plus cup 23.463 



Cup 12.863 



Net weight of butter. . 10.600 



First weighing 23.463 



Second weighing 21.784 



Net loss in weight 1.679 



"ffol X 100=rl5 - 8 % moisture. 



Determination of Per Cent Fat in Butter 

 Volumetric Methods 



The Volumetric methods of testing butter for fat, which have 

 been devised, are all modifications of the Babcock test. The modi- 

 fications refer almost exclusively to such changes in the type and 

 graduation of the Babcock test bottle as to make the bottle applica- 

 ble for the butter test. In these methods the butter is weighed into 

 the butter test bottle and the per cent fat is read off the graduation 

 on the neck of the bottle. 



The testing of butter by these methods cannot as yet be consid- 

 ered a complete success and the results have not as a whole been 

 entirely reliable. The chief obstacles with which the operator is 

 confronted in his efforts to determine the per cent of fat in butter 

 by the modified Babcock test are : 



1. The reaction of the sulphuric acid used in the test with the 

 salt contained in the butter. The reaction generates hydrochloric 

 acid gas which tends to char the fat and the escape of which causes 

 violent foaming to the extent of forcing a portion of the contents 

 out of the bottle. 



The danger of charring the fat has been largely overcome by 

 adding water before the addition of the acid and by filling the 



