METHODS OF MANUFACTURING POTATO CHIPS. 7 
HANDLING THE FAT IN MAKING CHIPS. 
If the sliced potatoes are put into oil which is at a low temperature, 
they take a long time to fry and absorb so much grease that they are 
both soggy and unpalatable. Moreover, the more grease consumed in 
frying, the greater the expense of the product. The aim of the hot- 
water bath in Miss Farmer’s* recipe was to coagulate the protein in 
the potatoes, thus searing the surface and making it impossible for 
much grease to soak in. The same result may be attained by heating 
the oil to a point just below smoking before the slices are put in. 
The higher the temperature that can be maintained, the sooner the 
surface of the potato will be crusted over and the less oil will pene- 
trate. The water on the raw sliced potatoes and the temperature of 
the inner frying basket itself will lower the initial temperature of the 
Tic. 4.—Weighing the slices of potatoes to determine the total loss in peeling and slicing. 
oil, and it will take several minutes for the water to boil away and the 
fat to regain the heat it lost. Fats do not “boil.” It is the water in 
the oil that makes it bubble when heated, and until this has been 
changed to steam and evaporated the temperature of the fat can not 
be raised much above 100° C. (212° F.). The hotter the initial tem- 
perature of the oil, the more quickly the water will be boiled away. 
As the water evaporates, the oil becomes still and the temperature in- 
creases rapidly. It should be reheated after each batch of chips is re- 
moved. ~The only certain laboratory method of determining the tem- 
perature of the fat is to suspend a thermometer in the center of the 
pan. 
1Farmer, Fannie Merritt. Op. cit. 
