The stage at which heated fat begins to emit smoke and impart an unpleasant flavor to foods. The higher the smoke point, the better suited a fat is for frying. Though processing affects an individual fat's smoke point slightly, the ranges for some of the more common fats are:
butter (350°F)
lard (361° to 401°F)
vegetable shortenings (356° to 370°F)
vegetable oils (441° to 450°F) — corn, grapeseed,
peanut and safflower oils all have high smoke points, while that of olive oil is relatively low (about 375°F).