Smoke point

The smoke point generally refers to the temperature at which a cooking fat or oil begins to break down to glycerol and free fatty acids, and produce bluish smoke. The glycerol is then further broken down to acrolein which is a component of the smoke. It is the presence of the acrolein that causes the smoke to be extremely irritating to the eyes and throat. The smoke point also marks the beginning of both flavor and nutritional degradation. Therefore, it is a key consideration when selecting a fat for frying, with the smoke point of the specific oil dictating its maximum usable temperature and therefore its possible applications. For instance, since deep frying is a very high temperature process, it requires a fat with a high smoke point.

The smoke point for an oil varies widely depending on origin and refinement.^[1] The smoke point of an oil does tend to increase as free fatty acid content decreases and degree of refinement increases.^[2][3] Heating oil produces free fatty acid and as heating time increases, more free fatty acids are produced, thereby decreasing smoke point. It is one reason not to use the same oil to deep fry more than twice.^[1] Intermittent frying has remarkably greater effect on oil deterioration than continuous frying.^[4]

Considerably above the temperature of the smoke point is the flash point, the point at which the vapors from the oil can first ignite when mixed with air.

The following table presents smoke points of various fats:

See also

• Boiling point
• Flash point
• Fire point
• Kindling point

References

• Cooking For Engineers: Smoke Point of Various Fats - another list of smoke points along with some discussion on the subject
• Good Eats: Cooking Oil Smoke Points
• The Culinary Institute of America (1996). The New Professional Chef (6th edition ed.). John Wiley & Sons.