Cooking with cast iron

What it is

A cast iron pan is the only piece of cookware that gets better the more you use it. Where non-stick coatings wear out and thin pans warp, a cast iron skillet treated well becomes smoother, slicker, and more valuable over decades, and can outlive the cook who bought it.

Cooking with cast iron is the practice of using heavy iron pans for searing, frying, baking, and roasting, taking advantage of the metal's ability to hold and radiate heat steadily. The mass that makes cast iron heavy is also its great strength; once hot, it stays hot, so a steak laid in it keeps searing instead of cooling the pan. That thermal stability is why it browns meat and crisps potatoes better than lighter pans.

The defining feature is seasoning, a layer of polymerised oil baked onto the iron that gives it a natural non-stick surface. Seasoning builds up over time as you cook with fat, and a well-seasoned pan releases fried eggs as cleanly as any coated one. This is why people are protective of their pans and why a good skillet is often handed down through a family.

Care is simpler than its reputation suggests. You avoid long soaking and harsh detergent, wipe or scrub it clean, dry it thoroughly to prevent rust, and rub on a thin film of oil. The old rule against soap is largely outdated with modern detergents, but drying still matters because bare iron rusts fast.

Most people start with a single skillet and are surprised how versatile it is, moving from stovetop to oven without a thought. The honest trade-offs are real: it is heavy, slow to heat, and reacts with very acidic foods, so a long tomato simmer can strip the seasoning. But for searing and baking, few pans match it, and a good one costs €30 and lasts a lifetime.

How it works

Heat management is the variable that separates good cast iron cooking from a smoking, sticking mess. The pan takes several minutes to heat through because the metal is thick, but once hot it holds that heat ferociously, far more steadily than thin stainless steel. Preheat it gradually over medium for three to five minutes rather than blasting it on high, which scorches the centre while the edges lag.

The seasoning is what makes it non-stick, and it builds over time. That dark patina is polymerised oil bonded to the iron, and every time you cook with a little fat it improves. A new or stripped pan needs seasoning: wipe a very thin layer of neutral high-smoke-point oil over it and bake upside down at 220°C for an hour, repeating a few times to build the base layer.

Food releases when it is ready, not before. A steak or piece of fish stuck fast to the pan will lift cleanly once it has formed a crust, so resist prying at it early. Let the heat do the work.

For searing, cast iron has no equal because it stays hot when cold food hits it, giving an unbroken crust where a lighter pan would lose its heat and steam the food instead.

Benefits

Perfect Sears and Crusts Naturally Non-Stick Over Time Lifetime Cookware Investment Most Sustainable Cookware Heat Science Understanding Professional Results at Home

What you need

Here's what to gather before you start. The essentials are marked.

Cast iron skillet (26-28cm)

Cast iron Dutch oven Optional

Flaxseed or vegetable oil for seasoning

Chain mail scrubber (for cleaning)

Stiff brush

Heat resistant handle cover

Oven mitts

FAQs

How do I season a cast iron pan, and what does seasoning even mean?

Seasoning is a layer of polymerised oil baked onto the metal that creates a natural non-stick surface and protects against rust. To season, rub a very thin layer of neutral high-smoke-point oil over the whole pan, wipe it back so it looks almost dry, then bake it upside down at around 220°C for an hour. Repeat a few times to build it up. Thin layers are the secret, since thick oil turns sticky and tacky.

Can I use soap on cast iron or will it ruin the seasoning?

A little soap is fine on modern seasoning, despite the old myth. Polymerised seasoning is bonded to the metal and won't wash off with a quick soapy scrub, so don't be afraid of it. What actually harms a pan is soaking it in water (which causes rust) or scrubbing the seasoning off with harsh abrasives. Wash, dry immediately and thoroughly, then wipe with a touch of oil.

Why is food sticking even though it's supposedly non-stick?

Usually the pan isn't hot enough, or the seasoning is still building. Cast iron needs proper preheating, since adding food to a cold or barely-warm pan makes it grab. Let it heat for several minutes, add fat, let that shimmer, then add the food and leave it alone, because it releases naturally once it's seared. A young pan also gets more non-stick with every use, so stick with it.

My pan has rust spots. Is it ruined?

Not at all, rust is completely fixable. Scrub the rust off with steel wool or coarse salt and a bit of oil, rinse, dry thoroughly over heat, then re-season as if it were new. Cast iron is nearly indestructible, which is why decades-old pans get passed down. The rust just means moisture got left on bare metal, so dry it well in future.

Are there foods I shouldn't cook in cast iron?

A few, mostly very acidic ones, at least early on. Long-simmered tomato sauces, wine reductions, and other highly acidic dishes can strip a young seasoning and pick up a metallic taste. Once a pan is well seasoned, brief contact with acidic food is fine. I'd also avoid delicate fish until the non-stick is well developed, since it's the most likely to stick and tear.