CREAM. 245 



where F— per cent of fat in butter, B — yield of butter 

 from lOO lbs. of milk, A =■ percentage churning. Under 

 ordinary conditions of creaming these formulas may be 

 simplified to 



/a = 6.67/ - 1.42, 



/^ = 5.77^. 



Fortmila for finding the per cent cream to be separated when 

 a certain fat content in the cream is 7t/a«/^^ (Fleischmann): 



_ ioo(/ - /,) . 



/, /i , and /a = per cent of fat in full milk, skim-milk, and 

 cream, respectively. 



HANDLING AND CARE OF. CREAM SEPARATORS. 



By J. D. Frederiksen, Little Falls, N. Y., Manager Chr. Hansen's 

 Laboratory. 



In selecting a separator, local conditions, space at dis- 

 posal, nearness to its manufacturer who can put it up, 

 be held responsible, and quickly attend to repairs, etc., 

 may be of importance, and the following points should be 

 considered: 



Thorough Separation. — All manufacturers claim that 

 their machines do perfect work, but they do not always 

 come up to the claims. Under normal conditions the meas- 

 ure for thoroughness of separation is the contents of butter-fat 

 in the skim-f?iilk as ascertaified by the Babcock test. The best 

 modern separators skim practically absolutely clean, and 

 there is now no excuse for anything but perfect skimming. 

 With normal milk at the proper temperature run into the 

 machine at the rate of the capacity claimed for it, no sepa- 

 rator should leave more than o.ije of butter-fat in the ski?n- 

 milk, which is the smallest percentage that can be ascer- 

 tained by the Babcock test with accuracy. 



The table below gives the grand averages for the per- 

 centages of fat found in the trials of a number of the 

 leading separators, conducted at the experiment stations 

 of Delaware, Cornell (N. Y.}, Vermont, Pennsylvania, and 

 Wisconsin. 



