MILK-PLANT OPERATION. 6 
In large cities there is a wide variation in the age of the milk 
received at the plants. Figures obtained from the principal dealers 
in five cities on the age of the milk when received showed variations 
of from 2 to 48 hours, a large proportion being from 12 to 24 hours old. 
The milk-plant manager should arrange to have the milk reach the 
plant as fresh as possible. He is, of course, dependent on train 
schedules. At some small plants near the source of production it 
may be advisable to receive the milk twice a day, as it can be kept 
cold at the plant more easily than at the farm. 
GRADING, SAMPLING, AND TESTING. 
Milk should be dumped and weighed as soon as received. Each 
can of milk must be examined to determine its condition. (Fig. 2.) 
Fig. 2.— Inspection of milk on arrival at plant. 
This may be done by smelling or tasting, and milk with objectionable 
flavors or odors should, of course, be rejected. Fingers or hands 
should never be put into milk. Spoons used for tasting should be 
rinsed thoroughly and sterilized after each use. 
As soon as the milk is dumped into the weigh can a sample should 
be taken for the butterfat test. It is to the interest of both dealer 
and producer to have the sample properly taken and the testing 
properly done. (Fig. 3.) This question is of special importance, 
as more milk is now bought on butterfat basis than formerly. A 
difference between the test at the country receiving station and at the 
city plant indicates inaccuracy at one place or the other. 
At small plants where the milk is dumped from the cans directly 
into the pasteurizing vat, it may be weighed in the cans. Where this 
is done a sample should be taken from each can, and care must be 
taken to mix the milk in the can thoroughly before taking the sample. 
Much more satisfactory results are obtained by the use of the weigh 
