Two properties that matter

Every pan material has two relevant thermal properties. Thermal conductivity measures how quickly heat travels through the material — from the hot spot directly above your burner to the cooler edges. High conductivity means even heat distribution. Low conductivity means heat concentrates where the burner hits and stays there. According to Harold McGee in On Food and Cooking, the differences are dramatic: copper conducts heat at approximately 400 W/(m·K), aluminum at 210 W/(m·K), cast iron at 52 W/(m·K), and stainless steel at just 16 W/(m·K). Copper heats and responds roughly eight times faster than stainless steel of the same thickness.

Thermal mass (or heat capacity) measures how much heat the pan stores. A pan with high thermal mass takes longer to heat up, but once hot, it resists temperature drops when cold food is added. A pan with low thermal mass heats quickly but loses temperature fast when you add a cold steak.

The tradeoffs between these two properties explain why no single pan material is ideal for every cooking task.

Cast iron and carbon steel

Cast iron has low thermal conductivity and very high thermal mass. It heats slowly and unevenly — there are pronounced hot spots directly over the burner. But once fully preheated across the entire surface (which takes 10-15 minutes over medium heat), it stores an enormous amount of heat. That heat reservoir is what makes cast iron so good for searing: a cold steak lands on the surface and the pan barely drops temperature because there’s so much stored heat to draw from.

Carbon steel shares similar properties but is thinner, lighter, and heats more quickly. It’s the standard searing pan in professional kitchens. It develops a seasoning layer just like cast iron — polymerized oil that fills microscopic pores in the metal, creating a naturally nonstick surface over time.

Both materials require seasoning and react with acidic foods. Don’t deglaze a cast iron or carbon steel pan with wine or tomatoes unless you’re prepared to re-season; the acid strips the seasoning and gives the food a metallic taste.

Stainless steel

Stainless steel has poor thermal conductivity — worse than cast iron. Left alone, it creates significant hot spots. High-quality stainless pans solve this with an aluminum or copper core: the outer layers are stainless (durable, non-reactive, dishwasher-safe), and the inner layer is aluminum or copper (high conductivity, rapid heat spreading). This construction, called tri-ply or multi-clad, gives you stainless durability with copper-quality heat distribution.

Stainless is excellent for sauce-making and deglazing because it doesn’t react with acidic ingredients. The fond it develops is outstanding. The surface will also show you exactly how hot your pan is: a properly preheated stainless pan has the Leidenfrost effect — a drop of water will ball up and skitter across the surface rather than evaporating immediately. This is the best indicator that the pan is hot enough to add oil and begin searing.

Nonstick and aluminum

Nonstick pans are aluminum with a PTFE (Teflon) or ceramic coating. Aluminum has excellent thermal conductivity — better than stainless, far better than cast iron — so nonstick pans heat quickly and evenly. The nonstick coating sacrifices some heat transfer efficiency and limits usable temperature (most nonstick coatings degrade above 230–260°C).

For delicate proteins — eggs, fish, crêpes — nonstick is genuinely superior because the food can’t stick and doesn’t need as much fat. For searing or high-heat work, it’s the wrong tool. The temperatures required for a proper Maillard crust push up against the temperature limits of the coating, and the smooth surface doesn’t develop the complex fond that makes a pan sauce worthwhile.

Matching pan to task

Searing steak or chops: cast iron or carbon steel. Sauce-making and deglazing: stainless (multi-clad). Eggs and fish: nonstick. Even sautéing of vegetables: stainless or carbon steel. Low-and-slow dishes like cornbread or frittata that go from stovetop to oven: cast iron (oven-safe to any temperature). The pan isn’t the limiting factor in most cooking — but choosing the right material for the technique makes the result noticeably better.

Sources