Cast Iron

Cast iron puts iron into food, and that is well established rather than controversial. A study of iron ingots in Cambodian cooking measured 76.3 micrograms of iron per gram added to lemon water against 3.3 in fish soup - a 23-fold spread showing that acidity, not heat, is what drives the transfer. For most people this is neutral to mildly useful. Adult men and post-menopausal women need 8 mg of iron a day and menstruating women 18 mg, against a tolerable upper intake of 45 mg set on gastrointestinal distress, and the iron from a pan is non-heme iron, which the body absorbs poorly and absorbs less of as your stores fill. Iron overload is the real exception, and it deserves to be stated accurately: about 1 in 225 people of Northern European ancestry carry two copies of the C282Y mutation behind hereditary hemochromatosis, but the US NIDDK's own diet page for the condition does not mention cookware and says most people with hemochromatosis do not need to change their diet to eat less iron, because phlebotomy dwarfs dietary effects. Avoid cast iron if you have hemochromatosis is folk advice, not clinical guidance - it is a question for your clinician, not for a pan review. One regulatory curiosity worth pre-empting: the FDA Food Code restricts cast iron in commercial kitchens to cooking surfaces and cook-to-serve vessels rather than general food-contact equipment. Read that alongside the same section's demand that surfaces be nonabsorbent and easily cleanable, and it is a commercial warewashing rule, not a verdict on the pan in your kitchen. Lead is not a plausible concern in bare iron; the lead question on cast iron is about coloured enamel and brass trim, and it lives on the Porcelain Enamel page.

The reason to own one. Cast iron is denser than aluminum and stores more heat per unit volume, so a hot pan stays hot when cold food hits it - it buys thermal mass, not conductivity, and heats unevenly until it has had time to equalise. Seasoning is built at oven temperatures around 375 to 500 F (190 to 260 C), above the smoke point of whatever oil you use, which is why oil choice and oven temperature interact: unrefined flaxseed smokes at 107 C while refined avocado holds to 271 C. There is no upper kitchen temperature that hurts the metal, and no plastic anywhere in the picture unless the pan has a bolted-on handle.

Heavy, magnetic, matte black-brown, and the surface has depth to it rather than the uniform slickness of a sprayed coating. Look at the rim and the handle join: seasoning wraps the whole pan continuously because it was wiped on, whereas a nonstick coating stops at a visible edge and is usually a different colour from the metal. Enamel is glossy, often coloured, and chips to reveal grey iron rather than flaking. If a pan is sold pre-seasoned, the fair question to a brand is which oil - Lodge, for instance, states soy-based vegetable oil baked at high temperature - and a brand that will not name the substance on the cooking surface has told you something.

Dry it on the heat, keep a film of oil on it, and it outlives you. What actually degrades a pan is standing water, long soaks, and acid: America's Test Kitchen simmered tomato sauce in seasoned and unseasoned skillets and found no metallic taste at 15 minutes but a clear one at 30, far worse in the unseasoned pan, so the practical rule is that acid is fine briefly and a problem at length, and seasoning quality is the variable that decides which. Rust is a repair job, not a write-off - scour it back to metal, wash, dry, oil thinly and bake at 450 to 500 F for an hour. Cast iron is brittle by nature, so the one genuinely fatal event is dropping it.

Effectively immortal. A neglected pan is restorable and a cracked one is still iron scrap with real value at any scrap yard. This is the rare kitchen object where the honest end-of-life answer is that there usually is not one.