Tell when oil is about to smoke by watching convection movement

Watch for oil changing from perfectly smooth to visible convection movement, then add food just before it starts smoking.

From ChefToddMohrWatch this bit

cooking oil

saute pan

As oil heats, it begins circulating (rising and falling) even in a very thin layer. Soon after this convection begins, the oil will smoke; the goal is to add the protein just before visible smoke appears.

The short version

Convection movement in oil is a visual cue that smoke is imminent.
Add protein just before visible smoke for proper sauté heat.
Different oils have different smoke points.

What you need

saute panAny pan suitable for heating oil
stoveHeat source

How to do it

1
Heat oil in a pan and observe its surface as it warms.
You’re looking for the transition from smooth/still oil to subtle movement.
Watch this step
2
When you see convection movement begin, prepare to add the protein.
This is the warning sign that smoke is coming soon.
Watch this step
3
Add the protein to the pan just before there is visible smoke.
If the oil is already smoking, start over—don’t cook with smoking oil.
Watch this step

What goes wrong

Adding protein when the oil is not hot enough (no reaction).

Wait until the oil shows convection movement before adding the food.

Letting oil smoke and continuing to cook with it.

Discard/replace the oil and reset the heat; avoid cooking with smoking oil.

Why it works

Adding food at the right pre-smoke moment indicates proper heat management and helps achieve the intended sear/sauté reaction without burning the oil.