16 
TESTING AND HANDLING OF MILK AND CREAM 
until the cream is uniform in color, and smooth. Cream samples con¬ 
taining lumps or streaks must be classed as not thoroughly mixed, 
and should not be tested until all lumps and streaks have been dis¬ 
solved. 
To insure accuracy, all samples of cream should be tested in 
duplicate. If the results of the duplicate tests do not agree, there is an 
error somewhere and the work should be repeated. Then, also, if 
something happens to one test, the other is left. 
Weighing the Test .—After again making sure that the scales are 
level and balanced, weigh out the test immediately, nine or eighteen 
grams, using a large mouthed pipette to transfer the cream to the test 
bottle. No cream should be allowed to get on the outside of the bot¬ 
tle or in the scale pan while the weighing is done. 
I o lengthen the life of the scales, use the rest rod whenever adding 
weights or taking weights from either scale pan. 
If too much cream should be added to the test bottle, the excess 
may be removed with a clean wire or glass rod. Be sure to get the 
weight accurate, a.s not quite enough or a little too much will not 
bring correct results. 
One-bottle torsion balance scale 
Four-bottle torsion balance scale 
Adding the Acid .—Before adding the acid the cream should be 
brought to between 60 and 70 degrees F. by placing in a water bath of 
that temperature or colder until the cream has reached the desired 
temperature. Unless the cream and acid are brought to the above tem¬ 
perature at the time of mixing, the action of the acid may cause burnt 
or cloudy tests. In cold weather it will be necessary to warm the acid 
slightly in order to bring it to the desired temperature. 
The proper measure of acid to be added will depend upon the size 
of the test, whether nine or eighteen grams, the strength of the acid 
and‘the richness of the cream. For a nine gram test, about 8.8 c. c. of 
acid may be used, for an eighteen gram test 17.5 c. c. of acid is the 
usual amount. While adding the acid, the bottle should be held at an 
