SEPARATION OF CREAM. 141 



Machines are now made, and are on the market, which will 

 bring the milk, or the fat-globules in the milk, into such a 

 condition that they cannot be separated from the milk. The 

 process is called "homogenization." It consists of bringing 

 the milk under certain pressure, and then forcing it out through 

 a special valve. This rehef, through this special valve, causes 

 the fat-globules to divide up into very minute ones. They 

 divide up to such an extent that they cannot be separated 

 from the milk by gravity methods, and it is impossible to get 

 a complete separation by centrifugal methods. Homogeniza- 

 tion of milk is carried on to some extent in Europe. The 

 process practically insures uniform quality to the milk patrons 

 in the distribution of milk in cities, and secures a more uniform 

 consistency of the product. 



2. Condition of the Milk. — In order to get complete separation, 

 and keep the separator in good running order, it is essential 

 that the milk should be in as good physical condition as possible. 

 Coagulated, slimy, or otherwise viscous milk separates with 

 difficulty. When such milk is on hand it should not be mixed 

 with the milk that is in good condition, as it might tend to coag- 

 ulate more of the good milk, and the coagulated or slimy lumps 

 are hkely to clog the separator. Such milk should be left 

 until all the good milk has been separated. Then, if the coagu- 

 lated or slimy milk is thoroughly stirred so as to reduce the 

 lumpiness of it, it may be run through the separator success- 

 fully. It is a good plan not to feed the separator quite so 

 heavily when this quahty of milk is being run through. By 

 shutting off the inlet a little, it will usually run through without 

 clogging. Milk containing impurities in suspension should be 

 thoroughly strained previous to separation. 



Overfeeding the Separator. — When a separator is being 

 overfed with milk there is a tendency for the machine to do 

 less complete work. This is due to the fact that the more 

 milk is being fed into the separator the less time it will be 

 exposed to the centrifugal force. It is impossible to underfeed 

 the separator as well. As has been mentioned before, the 



