Preheat your cast iron gradually, but it's not complicated

Yes, you should preheat slowly to avoid warping—but the risk is mostly on thin modern pans or induction cooktops.

Warping happens when parts of the pan heat much faster than others. Cast iron is brittle—it doesn’t bend, it cracks or warps permanently. The slower you bring it up to temperature, the more even the expansion. That said, you don’t need to be precious about it.

On gas or electric coil: Medium-low for about 5 minutes, then bump to your cooking temp. That’s it. Start dry, then add oil after a few minutes if you’re searing. The flame wraps around the pan, so hot spots aren’t as extreme.

On induction: This is where you actually need to be careful. Induction heats the pan directly and fast—the center gets hot while the edges stay cool. Start on the lowest setting (2 or 3 out of 10) for 3 minutes, then increase by one notch every 2 minutes until you hit your target. Total time: 8-10 minutes. Don’t skip this.

General rules: Never go straight to high. Never put a cold pan on a hot burner. And if you hear a pinging sound during preheat, you’re heating it too fast—that’s the metal straining.

The thick vintage pans (like old Griswold) are harder to warp than the