The smoke point is the lowest temperature at which clearly visible smoke evolution begins above a heated oil or fat.
Contrary to the definite instructions for pre-heating the pan or fat in many recipes, for health reasons fats and oils may not be heated to the point at which smoke develops, as this can set acrolein free. The smoke point of a fat depends primarily on the fraction of free fatty acids: the larger this fraction, the lower the smoke point. A fat or oil that has already been heated several times (e.g. for frying) has a higher content of free fatty acids than a «fresh» one. As a rule, native oils have a higher content of free fatty acids than refined oils.
|Product||Smoke point °C|
|Peanut oil (refined = hot-pressed)||230|
|Peanut oil (unrefined = cold-pressed)||170|
|Palm kernel fat||220|
|Most refined oils||> 200|
|Cold-pressed rapeseed oil||130–190|
|Cold-pressed olive oil||130-180|
|Sunflower oil (refined)||210-225|
|Sunflower oil (unrefined)||107|
|Sesame seed oil (unrefined)||177|
|Mustard seed oil||254|
|Walnut oil (unrefined)||160|