140 American Milk- Condensing Factories. 
according to the character of product which it is desired to obtain. 
After the cream is taken off, the milk may be drawn at once 
into the vacuum-pan, simply b}' running- a rubber hose from the 
milk to the pan, as the suction produced by the vacuum in 
the pan is sufficient to draw the milk through the pipes. During 
the process of condensing, the temperature in the pan is kept at 
about 135°, a vacuum of from 22 to 25 inches being meintained. 
The milk having been reduced to its proper consistency, is 
drawn from the vacuum-pan into the cooling-pails, which are 
immediately plunged into the vats containing cold spring water. 
The pails are about half filled, the average temperature of the 
water being 52° Fahr. When thoroughly stirred and cooled it 
is ready to go into the non-conducting shipping cans to be trans- 
ported to market. The plain condensed skimmed milk brings 
25 cents (one shilling) per quart. 
Under this process, in the month of July, when the daily 
delivery of milk was between 5000 and 6000 quarts, 8 quarts of 
milk yielded 1 quart of cream, and the whole quantity of cream 
made 400 lbs. of butter per day. 
When whole milk and skim milk are used together for con- 
densing — I he evening's milk having been strained and placed in 
the small tin cooling-pails — they are taken to the water pools or 
tanks, and are surrounded with flowing spring water on the 
same plan as at the butter factories. 
Here the milk sets until morning, when the pails are taken out, 
and the cream is dipped off. The skimmed milk is then imme- 
diately drawn into the vacuum-pan. In a vacuum of about 24 
inches the milk will begin to boil when the mercury indicates 
100" Fahr. The heat soon rises to 135^ or 140°, and is allowed 
to go no higher. The morning's milk, as fast as it is delivered, 
goes to the pools the same as the night's milk, and after the 
milk in the vacuum-pan has been somewhat reduced in volume, 
the morning's mess is taken from the pools, and is drawn into the 
pan, and the mixture then reduced. 
By this process it is stated that a tolerably fair product of 
plain condensed milk can be made ; while for sugared milk some 
operators think a more uniform product, or the "smoothest milk" 
is made from milk that has had about half its cream removed 
before going to the pan. 
One of the leading difficulties in the condensing process is 
to carry the milk along, and draw it from the pan before it is 
in a condition to granulate on cooling. It should be " smooth," 
and not gritty under the tongue, the latter state arising, from 
the sugar of milk assuming a granulated form. When milk is 
treated in this way no saltpetre is added, or indeed any other 
chemical. The use of such substances to clarify the milk is 
