This section is from the book "The American Woman's Cook Book", by Ruth Berolzheimer. Also available from Amazon: The Domestic Arts Edition of the American Woman's Cook Book.
Fats for deep fat frying, should be capable of being heated to a high temperature without smoking or burning. Smoking impairs the flavor, the digestibility and the durability of fat. A fat should be capable of being used over and over again, but everytime the fat is used the smoking temperature will become lower, because of the amount of crumbs or other foreign matter which escapes from the food into the fat, unless the fat is always strained carefully after frying and clarified frequently.
Vegetable Fats and Oils are used increasingly for frying. They have high smoking temperatures. They can be used over and over again and are not likely to burn. They absorb practically no odor from the food so can be used for all sorts of foods. They are, perhaps, the best all around fats for general use in frying. See photographs opposite.
Olive Oil has a comparatively low smoking temperature. This is partly compensated for, however, by the fact that it produces smoke slowly and the smoke is non-irritating. It has more decided flavor than the other vegetable oils.
Lard must be used with great care to avoid overheating, and must be well clarified after each time of using. It has a rather low smoking temperature, smokes rapidly and produces an irritating smoke. Like all animal fats, it absorbs strong odors from foods.