How cookware materials conduct and hold heat

Conductivity vs heat retention

Conductivity is how quickly heat moves through the metal. A highly conductive pan spreads the burner's heat sideways across the base and up the walls, so there are fewer hot spots, and it reacts fast when you raise or lower the flame. Heat retention depends on how much heat the pan can store, which comes from both the material and how much of it there is. A thick, heavy pan stores more heat and loses less temperature when cold food goes in.

These properties often pull in opposite directions. Copper is a superb conductor but a thin copper pan cools quickly when you add a steak. Cast iron is a poor conductor, so it heats unevenly at first, but a heavy skillet holds a lot of heat once it gets there. Understanding which one you need for a dish is the key to choosing a pan.

How the common materials compare

The rankings are relative and describe typical pans. Thickness changes the picture a lot: a thick aluminum pan holds more heat than a thin one, and a thin cast iron pan holds less than a heavy one.

Copper and aluminum: fast and even

Copper conducts heat better than any other common cookware metal. A thick copper pan heats evenly edge to edge and follows burner changes almost instantly, which is why it is prized for sauces, caramel and delicate fish. It is expensive, heavy at good thicknesses, and reacts with acidic food, so copper pans are usually lined with stainless steel or tin. See copper cookware explained and copper cookware care.

Aluminum conducts heat well at a fraction of the cost and weight. Bare aluminum reacts with acidic food and scratches easily, so it is usually anodized, coated with nonstick, or used as the core inside stainless steel. Most nonstick pans are aluminum underneath.

Stainless steel and cladding

Stainless steel on its own is a poor heat conductor. A pan made only of a single layer of stainless will have hot spots right over the flame. That is why quality stainless cookware is clad: layers of stainless steel bonded around a core of aluminum or copper. The stainless gives a durable, non-reactive cooking surface; the core spreads the heat.

Tri-ply has one aluminum core; 5-ply adds more layers for a thicker, slower, steadier pan; copper core uses copper in the middle. Disc-bottom pans put a thick disc only on the base, leaving thin steel walls that heat less evenly. Our what is clad cookware page and All-Clad D3 vs D5 comparison explain the trade-offs.

Compare clad stainless cookware sets →

Cast iron and carbon steel: stored heat

Cast iron conducts heat slowly, so a skillet on a small burner will be hotter in the middle than at the edges for a while. Preheat it longer, or in the oven, to even it out. Once hot, its mass holds that heat, which gives a deep sear on steaks and keeps oil temperature stable for frying. Enameled cast iron behaves the same way, and in a Dutch oven that steady stored heat is exactly what a braise needs.

Carbon steel is thinner than cast iron, so it heats faster and responds more quickly, but it holds less heat. It suits high-heat searing and stir-frying where you want the pan hot fast. See carbon steel vs cast iron and how to preheat pans.

Matching material to the job

Most kitchens are best served by a mix: a clad stainless skillet and saucepan, an enameled Dutch oven, and a cast iron or carbon steel pan. Our how to choose cookware page helps you build that mix without buying pieces you will not use.

• Searing steaks and chops: cast iron, carbon steel or a thick clad stainless skillet.
• Braising and stews: enameled cast iron Dutch oven for steady heat. See the best Dutch ovens.
• Pan sauces and sauteing: clad stainless or copper for quick response.
• Delicate sauces and caramel: copper or thick clad stainless.
• Eggs and fish: nonstick aluminum or well-seasoned carbon steel.
• Boiling pasta and stock: lighter stainless or aluminum pots, which heat a large volume quickly.
• Induction cooktops: any pan with a magnetic base. See induction-compatible cookware.

Frequently asked questions

What is the best material for cookware? There is no single best. Clad stainless is the most versatile everyday choice; enameled cast iron is best for braising; copper gives the most control; nonstick is easiest for eggs.

Does cast iron heat evenly? Not at first. It conducts slowly, so preheat it gradually. Once hot, it holds heat very well, which makes cooking feel even.

Is copper better than aluminum? Copper conducts heat better and responds faster, but it costs much more and needs more care. Thick aluminum inside clad stainless gives most of the benefit for less money.

Why does my stainless pan have hot spots? It may be single-ply or disc-bottom, or the burner may be smaller than the pan. Fully clad pans with an aluminum or copper core spread heat more evenly.