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Tut MoyoNNiER TEs1 37 
POWDERED MILK AND MALTED MILE. 
Method of Sampling. 
Mix the sample thoroughly, making sure that it is sufficiently 
pulverized and representative of the entire lot to be tested. Trans- 
fer the pulverized sample promptly to a sealed jar. Mix hefore 
removing portions for testing. 
Butter Fat Determination. 
(1) Weigh out rapidly, to prevent absorption of moisture 
from the air, about one gram of milk powder into butter boat. 
In case of malted milk, weigh out a 0.5 gram sample. 
(2) Add 8&5 c.c. of hot water to flask. Insert cork. Tleat 
flask in water bath and shake thoroughly until the sample is 
well mixed. 
(3) Add 1.5 c.c. (one charge) ammonia, and shake thor- 
oughly. 
(4) Add alechol up to line on small neck of flask. Insert 
cork. Replace flask into flask holder. Shake flask thoroughly 
with cork inserted. Use best quality cork only. 
(5) Cool dask by running cold water over lower end of 
extraction flask, if flask is very hot. This is not ordinarily 
necessary. 
(6) Add 25 cc. ethyl ether. Insert cork, shake vigorously 
until all butter is dissolved out of boat. Then add 25 c.c. pe- 
troleum ether and repeat operation. 
(7) Centrifuge flasks, turning handle thirty turns after cen- 
trifuge has reached a speed of about 600 R. P. M. 
(8) Pour off extractions into proper, weighed 31-inch alum- 
inum dishes. Repeat above extraction, adding first aleohol, then 
25 ¢.c. of each ether. Excepting for very accurate work a third 
extraction is not necessary. 
The second extraction will remove all but .10 to .15 per cent 
of the butter fat. For factory control work this would be a good 
margin of safety. 
(9) Ewvaporate off ether at 135 degrees C. on “fat plate.” 
and when all of ether is off, dry fat in fat oven held at 135 de- 
grees C. for five minutes after the vacuum has reached at least 
twenty-two inches. 
(10) Cool, weigh and calculate per cent butter fat. 
