28o DAIRY TECIIXOLOGY 



which the raw material for oleomargarine must undergo, 

 because the processes of manufacture, especially in the 

 United States, are considered to be trade secrets. 



The caul fat of freshly killed beeves is, after a thorough 

 washing, first in tepid water, then in ice water, allowed to 

 stand in a cold room until thoroughly chilled. It is then 

 rendered between a temperature of 130° and 175° F. The 

 resulting oil is allowed to cool slowly until a considerable 

 portion of the stearin and palmitin has crystallized out. 

 This pasty mass is then subjected to hydrauhc pressure. 

 The oil or fluid part (about two-thirds of the whole) flows 

 out into a tank of cold water, where it soHdifies into a 

 granulated mass known to the trade as " oleo " oil, or 

 simply " oleo." The name " oil " is somewhat misleading, 

 as the product is a granular solid of a dull whitish color. 

 Fresh leaf fat treated in exactly the same way as the beef 

 tallow yields the " neutral " lard or " neutral " of the trade, 

 also a granular solid of a white color. 



The objects of this treatment are twofold: to produce 

 fats as free as possible from taste and odor ; and to remove 

 some of the stearin and palmitin, in order that the finished 

 product may have a lower melting-point. 



The " oleo " and the " neutral " are then mixed. The 

 proportions vary according to the marketing place of the 

 product (a warm chmate calling for more "oleo," a cold 

 one for more " neutral ") and the amount of butter with 

 which the mixture is flavored. This mixing is done in 

 large, steam-jacketed vessels provided with revolving 

 paddles, by which their contents can be easily mixed. 

 Here the " oleo " and the " neutral " are thoroughly 

 agitated with a certain proportion of milk (soured by in- 

 oculation with a pure culture of lactic-acid bacteria), 

 and sometimes with cream, butter and cottonseed oil, 



