154 SEPARATION OF CREAM 



Diluted with 25 per cent water, set at 60 F. (39 trials), 0.77 

 per cent fat in the skim-milk. 



Undiluted, set at 60 F. (30 trials), i.oo per cent fat in the 

 skim milk. 



Undiluted, set at 40 F. (30 trials), .29 per cent fat in the 

 skim-milk. 



A test of .77 per cent, where the milk is diluted to the extent 

 of 25 per cent, means a greater loss of fat than where the skim- 

 milk from undiluted milk tests i.oo per cent. 



It will be noted that, in his trials under the dilution method, 

 Wing set the milk at 60. The reason for this was that advocates 

 of the system contended that it would bring about such a speedy, 

 and yet complete, separation that it was unnecessary to* adopt 

 low temperatures. Wing's experiments prove two things; 

 first, that whether milk is diluted or undiluted the loss of fat is 

 heavy if the setting temperature is high, and, second, that where 

 the milk, without dilution, is set at a low temperature the cream- 

 ing coefficient is quite satisfactory. 



The valid objections to the dilution method are as follows : 



Much more bulk to handle, the use of a larger number of cans, 

 and increased labor. 



Danger of contamination of the milk and cream through the 

 use of impure water. 



Impairment of the value of the skim-milk for feeding. 



Injury to the cream or butter the product has an unde- 

 sirable, flattish flavor. 



The loss of fat in the skim-milk is too great, as the experiments 

 by Wing show. 



CENTRIFUGAL CREAMING 



In the separation of cream by centrifugal machines, the 

 same principle is used as in the gravity system of separation. 

 The only difference is that in the centrifugal method the force 

 which separates the cream from the milk is generated by artificial 

 methods, and acts in a horizontal direction ; in the gravity system 

 the force which separates the cream from the milk is only that 

 which results from the difference in the specific gravity of the 



