The main purpose of this study was to compare the frying life of lards and other fats when used under household conditions. Doughnuts and potato chips were cooked in the fats. Certain chemical and physical constants of the fats were determined before and after cooking to find the extent of change during their use. In addition, the amount of fat absorbed by the doughnuts was recorded and an effort made to determine whether the degree of absorption was correlated with the chemical and physical characteristics of these fats, and if so, with which of these characteristics.

In another unit of the study doughnuts were cooked at three temperatures, and the extent of the chemical and physical changes in the fats, due to the temperatures employed, was determined. The doughnuts cooked at these three temperatures were also scored for palatability.