Farm Dairying 253 



0.1 to 1 per cent of fat in the skim-milk. An average 

 will be about 0.5 per cent. Very deep vessels are used 

 in the "deep setting method." The latter will give a 

 more complete separation where the temperature can be 

 kept low, leaving only about 0.3 per cent fat in the skim- 

 milk. Sometimes the "water dilution method" is used. 

 The fresh milk is diluted with an equal volume of water 

 before setting. This renders the milk unsuitable for 

 domestic use, and, besides, has been found to leave 

 more butter-fat in* the milk than any system of gravity 

 creaming. 



358. Centrifugal Creaming. The cream separator is a 

 machine for separating the cream from milk while fresh. 

 It separates cream much better, quicker and with less 

 work than gravity creaming. Good separators leave 

 only 0.02 to 0.08 per cent of the butter-fat in the milk. 

 The separator also gives a cleaner cream than can be 

 obtained by the usual methods. The effectiveness of 

 cream separators is due to the action of centrifugal force, 

 which has a tendency to throw the heavier particles to 

 the outside. Cream being lighter than skimmed milk, 

 it is thrown to the center and the skimmed milk thrown 

 to the outside of a rapidly revolving hollow ball. 



358a. Farmer Smith milked ten cows, giving an average of 

 6,000 pounds of milk per year. He used the gravity creaming pro- 

 cess and lost one-third to three-fourths pound of butter on every 

 hundred pounds of milk due to imperfect separation of the cream. 

 His neighbor advised the purchase of a cream separator which 

 would leave only one-twentieth pound of butter-fat in the milk, 

 telling him that besides saving the difference in butter-fat he would 

 be able to feed his calves the fresh-skimmed warm milk. Estimate 

 the difference and give your advice to Farmer Smith. 



359. Sanitary Dairy Products. In the production 

 of sanitary dairy products, great care must be observed 



