CONDENSED AND POWDERED MILK 467 



Manipulation of test. Carefully weigh 4.5 grams of well- 

 mixed evaporated milk into the 10 per cent test bottle. Add 

 one pipetteful of water. Add 17.5 c.c. of sulfuric acid and 

 shake until the curd in the test bottle is completely dissolved. 

 Whirl at usual speed (900 to 1000 revolutions per minute) for 

 five minutes. Mix equal portions of water and sulfuric acid in 

 glass beaker. For one or two tests one pipetteful of water and 

 one acid measure full of acid is sufficient. Fill test bottle to the 

 zero mark with this hot diluted acid. Whirl for two minutes 

 in tester, fill bottles to about the 8 per cent mark with hot 

 water, whirl for one minute and read the test at 140 F. The 

 fat column must be read from the top of the upper meniscus 

 to the bottom of the lower meniscus. Multiply the reading 

 by 4. This gives the correct per cent of fat. 



For making numerous tests from the same sample it is advis- 

 able to dilute the evaporated milk with equal parts of water, 

 by weight; then weigh nine grams of this dilution into the 

 test bottles and add one-half pipetteful of water. 



RAPID METHOD FOR DETERMINING SOLIDS IN UNSWEETENED 



MILK 1 



Hunziker worked out a formula for calculating the percentage 

 of solids when the per cent of fat and the Beaume hydrometer 

 reading at 60 F. were known. The formula is as follows : 



X 100 - 1000 X i + 1.2 X F 



P 

 145.5 BJ J 



B = Beaume hydrometer reading 

 F = per cent of fat 



Example: Evaporated milk tests 7.8 per cent fat and the 

 Beaume reading at 60 F. is 8.4. 



1 Indiana Report 1913, p. 43. 



