220 THE BUTTER INDUSTRY IN UNITED STATES [444 



than neutral lard. In the best grades some butter enters 

 into the product while in the cheapest grades the mass is 

 churned with milk, skim milk, or butter milk. Oleo oil and 

 neutral lard are chiefly manufactured by the packers, some 

 of which they use in their own oleomargarine manufacture. 

 Large quantities of these products are sold to establish- 

 ments exclusively engaged in the manufacture of oleomar- 

 garine. Oleo oil is also made in cities over the country 

 from fat collected from retail butchers. When the market 

 for oleomargarine is unfavorable much of the oleo oil is 

 used in the manufacture of other food products. 



Oleo oil is obtained from beef fat through the successive 

 steps of heating, settling, crystallization, and pressure by 

 which it is separated from the stearin and the fiber. In the 

 packing houses immediately after the slaughter of the ani- 

 mal the fat is removed and thoroughly washed in warm 

 water, after which it is chilled and hardened with ice water. 

 It is then minced finely with cutting machines, heated to a 

 temperature of 160 degrees F., agitated until the whole 

 mass is melted and then allowed to settle. Settling is ac- 

 celerated by spreading salt over the surface. After all the 

 fiber and scrap have settled to the bottom the clear oil is 

 siphoned into another vessel, where salt is again added and 

 the temperature controlled to allow further settling. After 

 sufficient settling has taken place it is siphoned into a vat 

 where it stands from three to five days. During this time 

 the stearin in the oil crystallizes. Part of it forms a crust 

 over the surface and part falls to the bottom. The whole 

 mass is then agitated until it is mushy, after which it is 

 wrapped in canvas cloths and gradually subjected to hy- 

 draulic pressure. The oil is forced out and the stearin, 

 which is the hard substance in fats and is most prominent 

 in mutton tallow, remains in the canvas cloths. The oleo 

 oil is then ready for use. It can be piped to the oleomar- 



