200 Condensed Miek and Milk Powder 



CHAPTER XXX 



CHEMICAL TESTS AND ANALYSES OF MILK, SWEETENED 



CONDENSED MILK, EVAPORATED MILK AND 



MILK POWDERS 



In assembling these methods of analysis, preference has been 

 given the "Official and Provisional Methods of Analysis," published 

 by the American Association of Agricultural Chemists. 1 The of- 

 ficial methods have been modified and supplemented by other 

 methods in numerous cases, wherever, in the judgment of the writer 

 and others, such modifications and substitutions are better adapted 

 for analysis of these special products. A special effort has further 

 been made to include in this chapter modifications and abbreviations 

 of tests and analyses, adapted for the use of the factory operator, 

 whose knowledge, skill, facilities and time are too limited to enable 

 him to successfully follow the directions of the official methods, or to 

 execute delicate and difficult chemical analyses. 



For practical factory tests of fresh milk on the receiving plat- 

 form, determining its fitness for condensing, the reader is referred 

 to Chapter III, "Factory Tests for Purity," pp. 29 to 34. 



MILK 



specific gravity 



Aerometric Method, by Means of the Quevenne Tactom- 

 eter. — Use an accurate Quevenne lactometer with thermometer 

 attachment, and a lactometer cylinder about ten inches high and 

 one and a half inches wide. Fill the cylinder with milk at a tem- 

 perature between 55 and 65 degrees F. Insert the lactometer and 

 when it has found its -equilibrium, note the point on the scale at the 

 surface of the milk. The correct temperature is 60 degrees F. For 

 every degree Fahrenheit above 60 add one tenth point to the ob- 

 served reading, and for every degree Fahrenheit below 60 deduct 

 one tenth point from the observed reading. This rule holds good 



1 United States Department ol Agriculture, Bureau of Chemistry, Bulletin No. WI, 1912 



