Can Nambu Ironware (Tetsubin) be used with induction heating?

"Can Nambu Ironware be used in induction heating coker?"

"I can’t buy Nambu Ironware since I use induction cooktop burner"

We have frequently received inquiries regarding this matter. Interestingly, Nambu Ironware is indeed compatible with induction heating, although this information remains relatively less disseminated. Bearing in mind the distinctive attributes of induction heating, I aim to elucidate the benefits and necessary precautions when employing Nambu ironware in conjunction with this method.

Nambu Ironware and Induction Heating is the best combination

Nambu Ironware, a quintessential traditional craft of Iwate Prefecture, embodies its rich heritage. With a history spanning 900 years, specifically within Mizusawa-Nambu, it is often associated solely with open flame methods like gas due to its artisanal reputation. However, it is worth noting that Nambu Ironware is also highly compatible with induction heating, a fact that might not be widely recognized. To delve into this compatibility, let's explore the mechanics and attributes of induction heating, shedding light on its synergy with Nambu Ironware.

Mechanism for heating cooking utensil itself

How Nambu ironware (Tetsubin) is heated by Induction Heating system

The distinguishing characteristic of an induction cooker is its ability to generate heat within cooking utensils like pots and iron kettles. Upon activation, the internal coil creates magnetic field lines. As a cooking utensil approaches the induction cooker, it induces an eddy current on its surface, leading to the generation of Joule heat due to the utensil's electrical resistance. Consequently, the cooking utensil itself becomes a source of heat, illustrating the fundamental principle of the Induction Heating system.

In simple terms, it involves cooking utensils that produce heat when subjected to an electric current.

Furthermore, the induction cooker boasts high thermal efficiency and mitigates the risk of fire by eliminating the need for direct flame, as seen in gas stoves.

Requirements for Cookware in Induction Heating

Despite the efficiency and safety advantages of Induction Heating, not all cookware can be utilized. Some materials do not respond to induction. Particularly, cookware made from clay pots, copper, and aluminum fall into this category.

Three conditions are essential for compatibility with Induction Heating cookers:

The material must be magnetically receptive.
The bottom diameter must meet or exceed the minimum size specified by the manufacturer of the Induction Heating cooker.
The bottom must firmly adhere to the Induction Heating cooker.
As elucidated in the mechanism of Induction Heating, the absence of magnetic properties in materials like aluminum, copper, and clay pots impedes the formation of vortex currents induced by magnetism.

Additionally, even if the material possesses magnetic attributes, inadequate sensor responsiveness may occur if the base is too small.

Bottom shape where Induction Heating is not available

Moreover, even when the bottom size is adequate, usage may be impeded if the Induction Heating cooker fails to adhere to the base due to protrusions or indentations.

Nambu Ironware is crafted from a material compatible with Induction Heating

The principal component of Nambu ironware is cast iron, comprising carbon and silicon. Iron possesses magnetic properties and possesses sufficient electrical resistance to generate Joule heat. Aligning with the attributes outlined in the aforementioned Induction Heating system, Nambu ironware inherently fulfills the prerequisites for cookware suitable for Induction Heating.

Two additional considerations are "bottom size" and "bottom irregularities." Given that each Induction Heating cooker features distinct specifications, I recommend consulting online resources using the product's name and model number to verify details such as size and surface evenness.

Employ an Induction Heating plate in cases of inadequate bottom surface size

When confronted with a mismatch between the bottom surface diameter and the heating requirements, resort to an Induction Heating plate. This metal adapter serves to indirectly heat cookware composed of non-magnetic substances like aluminum or those possessing small bottom dimensions, as exemplified by items like the Macchinetta (stove-top espresso maker). It is important to emphasize that this differs from an "Induction Heating mat" utilized for protecting the top plate from stains.

Advantage of utilizing Nambu Ironware on Induction Heating cooker

Boiling water with Nambu ironware imparts a gentle flavor and is known to enhance iron intake. This attribute holds true even when employing Induction Heating as the heat source. Let us explore the benefits arising from the synergy between an Induction Heating cooker and Nambu ironware.

Advantage 1 Heat-Resistant Handle

Given that Nambu ironware is crafted entirely from iron, its handle (crane) becomes hot when exposed to an open flame. As a consequence, there is a risk of burns when handling it directly to pour hot water. Ensuring safe usage necessitates the use of a potholder or kitchen mittens.

However, in contrast, when heated on an induction cooker, the handle experiences significantly less heat transfer than it would on direct flame. While care is still paramount to prevent burns, managing the vessel becomes less challenging compared to boiling water on a gas stove.

Advantage 2 Minimal Bottom Color Alteration

Recent years have witnessed a surge in the popularity of Nambu ironware, particularly with various colors, particularly in Europe. One advantage of employing Induction Heating is its minimal impact on the external color. When utilized on a gas stove, direct exposure to flame from the bottom to the sides can lead to gradual discoloration of the surface. Preventing such alterations necessitates controlling the heating intensity to keep the flame size beneath the bottom surface.

Conversely, when using an Induction Heating cooker, the absence of open flame ensures that color changes due to flame-induced discoloration are mitigated. While the evolving patina of Nambu ironware can be seen as a delightful consequence of usage, those who wish to preserve the original color may find utilizing an induction cooker more suitable.


Precautions for using Nambu ironware in Induction Heating

While there are numerous advantages to employing Nambu ironware alongside an Induction Heating cooker, certain precautions must be heeded.

Moderate Heat Usage to Prevent Deformation

The 200 V Induction Heating cooker offers a robust maximum heat output. However, it's important to exercise caution, especially concerning the risk of deformation. Rapid and concentrated temperature changes solely at the bottom can trigger variances in the coefficient of thermal expansion, potentially leading to deformation or damage. This advisory extends beyond Nambu ironware and applies to all cookware, including stainless steel and other materials. To avert such risks, it is advisable to utilize the product at a heat setting of "medium" or below, as indicated by a warning from the Consumer Center (*4).

Products with an Enamel Interior are Meant for Teapots

Items featuring a smooth glass enamel interior are not intended as "iron kettles" suitable for boiling water. Instead, they serve as "teapots" designed for steeping tea leaves with hot water. Should these be used for boiling water, the enamel coating might detach. This concern extends beyond Induction Heating; similar risks apply when using direct heat sources like gas. However, the broad temperature changes inherent to Induction Heating necessitate heightened vigilance.

Shifting focus slightly from Induction Heating, it's worth noting that teapot-style products with enamel-coated interiors feature a glass surface, ensuring rust resistance and ease of maintenance. However, they aren't effective for iron supplementation.

For those seeking Nambu ironware for boiling water or iron infusion purposes, I recommend verifying the presence of an enamel interior coating prior to purchase.


In Conclusion

Nambu ironware inherently complements Induction Heating. It is my aspiration that individuals who believed traditional crafts couldn't be utilized due to their induction heating-equipped kitchens will now consider embracing them.

With Nambu ironware on an induction cooker, the handle remains comfortably cool, in contrast to heating it on a gas stove. Moreover, it facilitates temperature stability, boasts commendable thermal efficiency, and contributes to electricity conservation due to its minimal heat loss.

Why not incorporate Nambu ironware into your daily routine, even in an Induction Heating context? You can explore Induction Heating-compatible Nambu Tekki products at our Nambu Tekki studio OITOMI through our online shop, accessible via the follwing link.