Does iron cookware turn food black?

A common worry from customers switching from non-stick to iron is that their food will turn black or taste of metal. Sometimes it does, but only in certain conditions, and they are easy to avoid.

The darkening comes from a reaction between iron and acidic or tannin-rich ingredients. Tamarind, tomato, raw mango, kokum and vinegar all react with bare iron, especially when they simmer for a long time or sit in the kadai after cooking. The result can be a grey or dark colour and a sharp, metallic taste. Spinach and some greens can also darken.

Well-seasoned iron reacts much less, because the layer of polymerised oil sits between the metal and the food. That is why a new kadai behaves differently from one that has been used daily for a year. In the first month, use your iron for dry dishes such as poriyal, stir-fried vegetables, fried snacks and dosa, which actually build up the seasoning. Cook tamarind and tomato dishes in clay or tin-lined copper for now.

Even later, transfer sour dishes out of the iron kadai to a steel or clay bowl as soon as they are cooked, rather than leaving them there for the meal. Do not store leftovers in iron overnight. Wash, dry the kadai on the flame and wipe a little oil inside after each use. Following these habits, most families find their food tastes the same as before, and we make no claims beyond that. If your kadai keeps darkening food after months of use, bring it in and we will re-season it for you.