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CHAPTER VIII 



Methods of Testing Butter for Water 



Numerous methods designed for the determination 

 of water, adapted for creamery use, have been called 

 into existence by the enactment of laws controlling the 

 percentage of water in butter. All methods are based 

 upon the same general process ; the water is evapora- 

 ^ ted from a weighed portion of butter and the amount 

 removed is then ascertained usually by weighing the 

 dried residue, but in some cases by distilling and 

 measuring the evaporated water. The apparatus and 

 materials required for any of the methods can be ob- 

 tained at dairy-supply houses. The various methods 

 in use differ in the details and, before describing any 

 of them we will notice certain points of resemblance 

 and difference, such as relate to (i) preparation of 

 sample, (2) weighing of sample and amount used, 

 (3) evaporation of water, (4) ascertaining the amount 

 of water evaporated, and (5) calculation of percentage 

 of water in butter. 



PREPARATION OF SAMPLE 



The sample of butter must always be taken and pre- 

 pared with special care (p. 101), whatever method of 

 determining water is used. Unless the sample is truly 

 representative, the results of testing are useless or 

 worse. When only approximate results are desired, 

 it may answer the purpose to take samples directly 



no 



