Looking after cast iron teapots and kettles

What cast iron teaware do we carry?

We carry Ikenaga's Nambu ironware: teapots and kettles cast in Iwate Prefecture, the home of the Nambu tekki craft. The range runs from a smaller teapot meant for the table to larger kettles built to sit on the stove. A couple of design points recur across the range: the body and handle both get hot in use, so potholders are the habit, and several handles fold flat for storage while others do not. Every listing describes the pieces as handmade, so small scratches or unevenness are normal rather than a fault.

Enamel-lined teapot or raw tetsubin: which is which?

The two are not interchangeable, and the difference comes down to what lines the inside. A raw, unlined tetsubin is bare cast iron inside and out, and that bare iron is what it is traditionally used to boil water in. An enamel-lined piece has a coating baked onto the interior, which makes it easier to keep clean but also means it cannot go over direct heat, since the heat would crack the enamel. Every Ikenaga teapot and kettle we currently stock is enamel-lined. Some of those enamel-lined pieces are still rated for the stove, gas, induction or charcoal, because the maker built the enamel to handle it; others are teapots only, meant to hold water that was boiled elsewhere and poured in, not to sit over a flame themselves. Check the individual listing before you put any piece on heat, since the two types look similar from the outside.

How do you look after an enamel-lined teapot or kettle?

Wash it by hand, and skip the dishwasher completely. Ikenaga's own listings are consistent on this across the range: hand wash only, no detergent, no sponge and no scrubbing brush. Wiping the iron with a cloth while it is still hot is what brings up its shine, and the maker notes the surface gains character the longer a piece is used, so that dulling is part of how it is meant to look over time rather than a problem. Keep it off the microwave and away from an open flame unless the specific model is rated for direct heat, since body and handle both run hot regardless and a potholder is worth keeping nearby.

What about a raw, unlined tetsubin?

A raw tetsubin needs a different routine, mostly because there is no enamel standing between the iron and rust. A new one is typically seasoned first: rinse it, then boil plain water in it and throw that water out, repeating the cycle a few times before the first real use. After every use the interior needs to be properly dried, and the standard advice is to use the kettle's own residual heat with the lid off rather than just air-drying, since leftover moisture sitting in a cool kettle is exactly what turns into rust overnight. Storing it with the lid off in a well-ventilated spot, or wrapped in newspaper with a desiccant, keeps moisture from building up between uses. With ordinary use the interior develops its own protective layer, called yuaka, a calcium-based coating that forms with repeated use and makes the surface less prone to rusting; a little surface rust that shows up early on is not unusual and can often be worked off gently with a soft brush, or reacted with the tannins in brewed tea to turn it into a darker, more stable form of rust rather than scrubbed away. None of our current Ikenaga stock is a raw tetsubin, so none of this changes how to treat what is actually on our shelf; it matters if you already own an older or inherited piece, or if you are buying one elsewhere in the unlined style.