There is something I always notice with pans on the stove:
- With the burner on, if the pan contains oils, once its temperature crosses the oil's smoke point it begins to smoke. This part I understand.
- If I continue to heat the pan, eventually the smoking stops or lessens. I assumed this was because everything that could burn off did, except:
- If, after the point where the smoking stops, I turn off the burner, the pan immediately begins smoking heavily again, until its temperature cools back down below the oil's smoke point.
Why does #3 happen? Why does the oil stop smoking, but then begin smoking again the moment I am no longer adding energy to it?
Note that the smoking starts immediately when the burner is turned off -- as in, before the pan has had time to significantly cool down relative to the current temperature and the oil's smoke point (cast-iron, for example, cools a lot more slowly than a thin steel pan, but I see the effect in both). If I quickly turn the burner back on, the smoking will stop again. So it doesn't seem to be directly related to the temperature of the pan, but rather to whether or not I am adding energy to it (and even if it is related to the temperature,I don't understand why it would stop at high temperatures). This is the part that I do not understand.
It doesn't seem to matter what type of oil it is but if it helps to have a concrete thing to focus on let's use canola oil, smoke point ~204C (400F), contains a mix of fatty acids:
- ~4% C16H32O2 (Palmittic Acid) (Saturated)
- ~2% C18H36O2 (Stearic Acid) (Saturated)
- ~56% C18H34O2 (Oleic Acid) (Unsaturated)
- ~26% C18H32O2 (Linoleic Acid) (Unsaturated)
- ~10% C18H30O2 (Alpha-Linoleic Acid) (Unsaturated)
Also, I do not know if the type of heat source matters, but I see this both with gas and induction ranges (I do not have an electric range).