24 BULLETIN 769. U. S. DEPARTMENT OF AGBICUI/TUBS. 
for general household purposes and for the manufacture of lard and 
butter substitutes. 
Corn oil. or. as it is sometimes called, maize oil. is obtained from 
the small germ portion of our common Indian corn. Although the 
germ itself is about half oil, only from 3 to 6.5 per cent of the entire 
kernel is oil. Were it not for the fact that in the preparation of 
hominy feed, cornstarch, and brewers' grits, and sometimes in the 
making of corn meal and other corn products, the germ is more or 
less completely separated from the rest of the grain, corn oil doubtless 
would be a mere curiosity, as it would not pay to extract it. 
On the basis of the 1917 output of corn oil, which was approxi- 
mately IIS. 000. 000 pounds, if we assume that the germs from a 
bushel of corn will yield 1 pound of oil, 118,000.000 bushels of corn 
were used in those plants that produce corn germs as a by-product. 
The hominy feed plants, which use the dry process, obtain from 2 to 
2.5 pounds of germ per bushel of corn. As this germ is mixed with 
a good deal of meal, however, the oil yield is only about 0A pound 
per bushel of corn. The starch works, employing the wet process. 
obtain about 3.25 pounds of germ, containing 40 per cent of oil. 
from a bushel of corn, or 1A pounds of oil per bushel. Many of the 
distilleries, although they separate a low-grade oil germ, secure a 
larger yield of oil per bushel than the hominy works, as it is necessary 
for them to remove the germ almost completely from the rest of 
the corn. 
AIAXUTACTUEE AXD uses. 
In degerminating corn, two distinctly different processes are now 
in use in the United States. In the older one. called the wet process. 
the corn is soaked in dilute sulphurous acid for some time and the 
germ then separated from the rest of the grain. This yields a germ 
in which the oil is already rancid when extracted. In the newer 
process, usually known, as the dry process, the germs are removed by 
mechanical means vriihout the addition of water. If the corn is 
sound, this oil can be used for food purposes with little or no rehiring. 
The germs, after being separated, are cured until tough and leathery. 
They are then run through a series of flaking rolls which flatten 
them and break the oil cells but do not grind the material into a 
flour, which would be hard to hold in the oil presses. While hydraulic 
presses could be used, as in the cottonseed oil mills, the general prac- 
tice hi the United States is to run the germs directly from the flaking 
rolls into expellers similar to those already described in connection 
with the production of cottonseed oil (p. 12V 1 
Like cottonseed and hot-pressed peanut oil. corn oil is refined 
before being marketed for food purposes, but the crude oil can be 
used in making soap, paint, linoleum, and similar technical products. 
- r. S. De-ot. Agr. Yearbook (1916) Separate 691 gives a derailed description of the manufacture of 
corn oil. 
