360 BOARD OF AGRICULTURE. [Pub. Doc. 



securing a complete separation. As a rule, this method 

 leaves about 20 per cent of the fat in the milk. Milk test- 

 ing 5 per cent would have 1 per cent of fat left in the skim- 

 milk. If the process is carried out carefully, it is sometimes 

 possible to skim as low as .5 of 1 per cent. 



Deep Setting. — Some twenty-five or thirty years ago it 

 was discovered that if milk was set in vessels when first 

 drawn, and rapidly cooled at a temperature of 40° F., and 

 kept at that temperature for twenty-four hours, the depth 

 of the milk could be increased from four to twenty inches, 

 and the separation made much more complete in a shorter 

 time. Several so-called deep-setting systems have been upon 

 the market, the more common one in Massachusetts being 

 the Cooley process. This method hardly needs an extended 

 description, it having been in very general use among 

 Massachusetts dairymen. The tin cans employed are some 

 twenty inches deep by nine inches in diameter, covered with 

 tight-fitting covers, and hold eighteen quarts each. The 

 milk is placed in the cans as soon as drawn, and the latter 

 immediately completely immersed in water at 40° F. and 

 kept there for twenty-four hours. If the milk is from cows 

 that have recently freshened, there will not be much over .2 

 of 1 per cent of fat in the skim-milk. As cows become ad- 

 vanced in the period of lactation, the skim-milk frequently 

 contains from .5 of 1 per cent to as high as 1 per cent of fat. 

 Taking the year through, the skim-milk from a herd of cows 

 is liable to contain fully .5 per cent to 1 per cent of fat. If 

 the milk from a cow producing 6,000 pounds yearly with 4 

 per cent fat be set by this system, there is liable to be a 

 loss of some 24 pounds or more of butter in the skim-milk. 

 The cream obtained by the deep setting is thin, and varies 

 quite widely in the amount of butter fat it contains, the ex- 

 tremes being from 12 to 24 per cent, with a probable aver- 

 age of 17 to 18 percent. The disadvantages of this method, 

 aside from the loss of fat, consist in the length of time re- 

 quired to secure a separation, and the amount of ice con- 

 sumed. The chief advantage consists in the fact that no 

 power is required, the milk being poured from the milk pail 

 directly into the cans and allowed to remain in the water 

 until the skim-milk is drawn off. 



