4 BULLETIN 1055, U. S. DEPARTMENT OF AGRICULTURE. 
table oils and compounds were more satisfactory than the animal 
fats. The liquids were preferred to the semiplastic compounds, be- 
ing more convenient to use in quantities, less expensive, and less 
wasteful in utilization. 
Most manufacturers of commercial potato chips use cottonseed oil, 
a few use lard, and a few have experimented with coconut and corn 
oils. Peanut oil is not yet widely known and has been so far little 
used in the manufacture of potato chips, but there is no reason why 
satisfactory results should not be obtained if a highly refined, bland 
oil is put on the market at prices that will compete with the cotton- 
seed oil now in use. 
The smoking point of well- refined cottonseed oil is higher than that 
of most of the other frying mediums, a much more important factor 
Fig. 1.—First step in making potato chips. Weighing six medium-sized potatoes on a 
torsion balance. 
in frying potato chips than in frying doughnuts, fritters, or similar 
foods that must be cooked through as well as browned. Blunt and 
Feeney * have determined the burning point of a number of the cook- 
ing fats, and their investigations show that cottonseed oil has the 
highest burning point, 451° F. (232.7° C.), with two cottonseed oil 
derivatives very nearly the same, 450° F. (232.2° C.), and 448° F. 
(231.1° C.). Leaf lard smoked at 480° F. (221.1° C.), bulk lard at 
381° F. (194.0° C.) ; olive oi] at 347° F. (172.7° C.) ; two samples of 
peanut oil at 323° F. (161.6° C.) and 300° F. (148.8° C.), respec- 
tively ; and coconut oil at 277° F. (136.1° C.). 
Some of the samples of peanut oil used in these investigations were 
almost as highly refined as the cottonseed oil and had as high a smok- 
ing point, but others smoked at approximately as low a temperature 
* Blunt, Catharine, and Feeney, Clara M. The smoking temperature of edible fats. In 
Jour. Home Econ., vy. 7, No. 10, pp. 535-541. 1915. 
