Nambu-Gusseisen (Nambu Tekki) is a traditional craft originating in Morioka, Iwate Prefecture. Each piece is hand-cast using sand molds, giving it a distinctive texture and excellent heat retention — built to be part of daily use for years to come.
Before First Use: Seasoning Your Iron Kettle (Narashi)
Seasoning creates a mineral layer on the inside of the kettle that helps prevent rust and gives boiled water a milder taste.
Step 1
Fill the kettle to about 80% with mineral water (hard water) or drinkable tap water. Bring it to a boil and let it reduce to about one-third of the original volume. Do not let the kettle boil dry.
Step 2
Discard the water, refill, and repeat the process 3 to 4 times, or until the water runs clear. The number of repetitions depends on the water quality.
Step 3
Once the water runs clear, the kettle is ready to use.
Tips
- Never let the kettle boil dry
- Do not touch or scrub the mineral layer on the inside
- Handle with care — the kettle becomes very hot
Care After Use (Kettle)
- Empty out all remaining water after use
- Remove the lid and let it dry completely
- Use residual heat, or heat gently for about 30 seconds, to remove any remaining moisture
- Do not wash or scrub the inside; no detergent is needed
- Wipe the exterior with a dry cloth, paying particular attention around the lid and spout
Any remaining moisture can cause rust, even after seasoning.
If Rust Appears
Red rust or a metallic smell are not harmful to health. To reduce them:
- Rinse the inside lightly
- Fill the kettle to about 80% with water
- Add 1 teaspoon of green or black tea leaves
- Boil uncovered over low to medium heat for about 30 minutes
- Discard the water and tea leaves
Tannins in the tea help neutralize metallic odors.
Nambu ironware is valued for its durability, thermal performance, and timeless design. With proper care, kettles and teapots can be used daily for many years.
To learn more, please visit the MUSUBI Journal blog: How to Care for Nambu Ironware