Smoke Point
Smoke point is the temperature at which a fat begins giving off a steady stream of visible smoke, a sign it's breaking down chemically. Past that point, flavour turns bitter and acrid, and the fumes irritate your eyes and throat.
What's happening chemically
Fats are mostly triglycerides: three fatty acids attached to a glycerol backbone. As heat climbs, those bonds start to split, releasing free fatty acids. Glycerol then breaks down into acrolein, the sharp-smelling compound in the smoke.
An oil that already contains more free fatty acids, impurities, or bits of food will smoke sooner. That's why refining raises smoke point, and why reused fryer oil smokes at lower and lower temperatures.
Smoke points of common fats
Values vary by brand, refining, and freshness, so treat these as ranges.
| Fat | Approx. smoke point |
|---|---|
| Butter (whole) | 150 °C (300 °F) |
| Unrefined sesame oil | 175 °C (350 °F) |
| Lard | 190 °C (375 °F) |
| Extra virgin olive oil | 190–207 °C (375–405 °F) |
| Refined canola oil | 205–230 °C (400–450 °F) |
| Refined peanut oil | 230 °C (450 °F) |
| Clarified butter / ghee | 250 °C (480 °F) |
| Refined avocado oil | 270 °C (520 °F) |
Smoke point isn't the whole story
Oxidative stability matters just as much. It describes how easily a fat reacts with oxygen to form off-flavours and breakdown compounds. Extra virgin olive oil has a moderate smoke point but plenty of antioxidants and stable monounsaturated fat, so it holds up well in normal cooking. Some polyunsaturated oils with high smoke points oxidize faster during long frying.
Flavour also counts. Unrefined oils like toasted sesame or walnut taste best raw or as finishing oils, where heat won't dull their aroma.
Matching fat to method
- Searing and stir-frying (pan surface often 200–260 °C / 390–500 °F): refined avocado, peanut, canola, or ghee.
- Deep frying at 175–190 °C (350–375 °F): refined peanut, canola, sunflower, or rice bran oil, which stay stable over many minutes.
- Sautéing and roasting at moderate heat: olive oil or butter mixed with a little oil.
- Low heat and finishing: whole butter, extra virgin olive oil, toasted nut and seed oils.
Chef Fizz says: A wisp of smoke means it's time to add the food. A cloud means turn it down. Fast.
Common mistakes
- Preheating oil in an empty pan on high. Thin oil climbs past its smoke point in seconds. Heat the pan first, then add oil just before the food.
- Searing in whole butter. The milk solids burn. Sear in oil, then add butter at the end for flavour.
- Reusing frying oil too many times. Strain it after each use and discard when it darkens, smells off, or smokes at normal frying temperature.
If oil ever catches fire, cover the pan with a lid and turn off the heat. Never use water.
Questions
Is it safe to cook with extra virgin olive oil at high heat?
For most home sautéing and roasting, yes. Extra virgin olive oil typically smokes around 190–207 °C (375–405 °F) and is rich in antioxidants that make it resist breakdown better than its smoke point suggests.
What oil has the highest smoke point?
Refined avocado oil is among the highest, around 270 °C (520 °F). Refined safflower, refined peanut, and rice bran oils are also high, roughly 230–260 °C (450–500 °F).
Why does butter burn so easily?
Whole butter contains milk solids and water. The milk proteins and sugars scorch around 150 °C (300 °F). Clarified butter or ghee, with the solids removed, can handle about 250 °C (480 °F).
What happens if oil goes past its smoke point?
It breaks into free fatty acids and acrolein, which taste bitter and irritate eyes and lungs. Keep heating and it can reach its flash point and ignite. Turn the heat down and ventilate.