SEPARATOR CREAM. 183 



separation has proved less advantageous in my experi- 

 ments, because the cream to a great extent transmitted 

 the cooked taste to the butter. This was not the case 

 when only the cream was pasteurized, although the temper- 

 ature was the same in both cases. The difference doubtless 

 came from the fact that a quicker cooling could be applied 

 in the latter case. As I consider the presence of a cooked 

 taste in butter a very serious fault, I cannot recommend 

 pasteurizing milk intended for butter production, and shall 

 not therefore here enter into the details of the process. 



Distribution of Bacteria in the Centrifugal Process. 



The centrifugal method has still another advantage 

 over the old methods of cream separation, an advantage 

 of which is thought too little, viz., the ability to remove a 

 large number of bacteria in the milk, so that the separated 

 cream and skim-milk do not (as in the most favorable in- 

 stances in the older methods) contain the number of bac- 

 teria which were found before the cream was separated 

 from the milk, but contain even a smaller number than 

 before separation. I have verified in numerous trials that 

 a large number of the bacteria present in the milk treated 

 were removed from the cream and the skim-milk by the 

 centrifugal force and went into the separator slime. This 

 can be ascertained by comparing the number of bacteria 

 found in the milk before the separation with the number 

 found in the cream, skimmed milk, and separator slime 

 after the separation. I have made numerous examinations 

 of this kind, experimenting with milk poor in bacteria 



milk, .22 per cent fat the former analyses ranging from .11 to .17 

 per cent and the latter from .18 to .35 per cent. W. 



