Oitomi teapots and kettles (history, manufacture, use and care).

Kikuchi San from Oitomi

Are you looking for an authentic Japanese teapot or kettle? Then you may want to consider one made by Oitomi. Oitomi is one of the few companies that make their products in famous region of Iwate that are available to purchase outside of Japan.

Table of contents

  • Why buy Oitomi cast-iron
  • Company information
  • History of Oitomi
  • How Oitomi makes their ironware
  • Teapot vs. Tetsubin
  • Oitomi products
  • How to use an Oitomi teapot
  • How to care for your teapot
  • Conclusion
Complete guide to Oitomi cast iron
Learn about your Oitomi ironware including: history, products, care and tips to maintain your cast iron teapot.

Why buy Oitomi Ironware

Here’s why Oitomi is a good option if you’re looking for a cast-iron teapot. The company is one of the oldest working cast iron foundries in Japan and has manufactured ironware since 1848. Also with over 150 years of experience, they have mastered the art of producing beautiful and useable ironware that will last for many years.

I was lucky to visit the family-run foundry during my stay in Iwate. Here’s what I learned.

Oitomi cast iron
Hard-working Oitomi worker smoothing a teapot before it goes into the kiln for rust prevention.

Oitomi Table of information

Origins Oitomi makes their cast-iron products in the Iwate prefecture.
Iwate is the cultural center for cast iron manufacturing in Japan dating back over
900 years.
Oitomi was founded in 1848 by the Oikawa family that
also established the nearby Oigen foundry.
Cast-iron foundry
and headquarters

57 Mizusawaku Hadacho
Oshu, Iwate 023-0105
Google maps
Type of casting
Oitomi uses the popular and accurate method of
sand casting to make their products (Wiki).
Iron source
Iron is sourced from different countries and is processed and refined in Japan.

Oitomi also recycles iron onsite, sourced from within
Japan, such as building and bridge girders.
Products that don’t meet their quality control are recycled.
Oitomi doesn’t have retail stores. Instead, they focus on
forming strong partnerships with retailers of all sizes.

Here’s a link to their website if you’re interested
http://oitomi.jp (non-affiliate link).
Interior finishing
Your Oitomi cast iron will have one of three interior

1. Raw or bare cast iron (uncoated) usually for
tetsubin kettles

2. Enameled interior for teapots

3. Polymerized oil used on cookware and on kettles
(designed for those who are concerned with rust and are
unfamiliar using a traditional Japanese kettle)
Exterior finishing
Your Oitomi cast iron will have one of two exterior 

1. Urushi: which is the traditional and iconic Japanese lacquer

2. Polymerized oil: which has a natural matte black finish
Oitomi makes a variety of products hand poured into molds
which include: teapots, kettles, wind-chimes, and cookware.

Oitomi also partners with different industries to manufacturer cast iron.
Oitomi worker checking a sand mold
Sand molds are carefully checked.

Background and history of Oitomi

The Japanese company Oitomi was established in 1848. And located in Oshu, in the Iwate region of Japan. The company is one of the oldest workshops in the Southern Iwate Prefecture. And they are famous for their cast iron kettles and teapots. However, Oitomi also make a variety of cookware and wind-chimes.

Because the company makes their ironware in Iwate, it can be called Nanbu Tekki. If you want to learn more about Nanbu Tekki here’s an interesting in-house article.

For over 170 years, Oitomi has remained in the capable hands of the Oikawa family that also operates the sister company called Oigen. And you can click the link if you’re interested in seeing some more beautiful kettles.

Oitomi Foundry (flag with Oitomi logo)
The Oitomi logo (three oak leaves represent longevity)

However, both companies focus on manufacturing quality products, much of which is by hand. This is one of the reasons Oitomi is a trusted brand and recognized for its high-quality cast-iron products.

Oitomi foundry worker
Your Oitomi cast iron is made by the friendly people of Iwate.

Traditional and modern teapots and kettles

Although I prefer the look of a traditional cast-iron teapot, Oitomi makes not only traditional styled teapots they also have a new product range which is brightly colored and catered towards overseas markets.

Selection of Oitomi teapots for sale
If you want a traditional cast-iron teapot but prefer a dash of color then Oitomi has a modern take on the traditional Japanese cast iron teapot.

Their in-house designer can make a bespoke set of molds within two to three months. Or potential clients can also choose from over 2000 molds. From design to manufacture, it’s all done on-sight and finished to the client’s specifications. That could be one of the reasons why Oitomi’s been in business for over 170 years.

Table 2: How do Oitomi make their cast iron teapots and kettles?

As you enter the foundry you are surrounded by the essential
material to make cast iron. Hard coking coal and the key ingredient iron.

Making sand molds

Oitomi uses the method of sand casting instead of traditional
clay molding which is why you can buy a kettle or teapot at
a much lower price than one made in traditional clay molds.

But don’t be fooled into thinking it’s all done by machine.
There’s no production line here. Special sand is boxed and
then hauled into a pressing machine by hand. One box at a
Making ironware
Even with established Japanese companies like Oitomi, your
ironware is made similarly to smaller bespoke companies.
Iron is hand-poured into every mold.

Which is why I’d choose Japanese cast iron over low-cost
Even the smallest piece of ironware is thoroughly checked
for imperfections and rough edges smoothed

Otomi cast iron products are refired in a kiln. This attention
to detail separates Nambu Tekki from other ironware.

Heating the ironware to extreme temperates in a kiln
changes the surface of the iron from standard Fe3+ to Fe2+
not only is this a vast improvement in preventing rust, Fe2+
may have added health benefits.

If you want to learn more, you may find my article on called, Is cast
iron safe?
Lacquer and

Finally, Oitomi cast-iron products get either a lacquer finish
or oil finish on the exterior. Then the teapots are enameled
before its final rust prevention coating.

Either a traditional high gloss lacquer is applied called
Urushi or oil is polymerized onto the iron in a similar way
you may season your pan at home.
Oitomi cast iron foundry
Your cast iron teapot or kettle is made on-sight using sand molds. This is an interior mold called a Nakago

Tetsubins vs. cast iron teapots

A lot of people use the term tea kettle and teapot interchangeably. But, when it comes to Japanese cast iron, these two are not the same thing.

  • A Japanese cast iron tea kettle is also called a tetsubin. You use a kettle to boil water for tea.
  • A cast iron teapot, on the other hand, is strictly used for steeping tea. That is because cast iron teapots have an enamel lining on the inside that makes them unsuitable for stovetop use. Extreme heat will crack the enamel. It is important to keep in mind the differences between these two when choosing a cast iron teapot or kettle.
Side-by-side example of a Tetsubin and teapot
Do you have an Oitomi teapot or kettle? Here’s a great side-by-side comparison. Note the larger kettle on the left is not enameled white the smaller teapot on the right has an enamel lining.

Ask your teashop or department store for Oitomi 

Oitomi makes several teapots and kettles unfortunately they are mostly available in Japan. However, your local teashop or department store might stock Oitomi products so be sure to ask and look for their logo of three oak leaves in a circle.

They also sell online. Here are a few of their offerings available at the time of writing.

Display of Oitomi cast iron kettles and teapots
Here’s some of Oitomi cast iron teapots and kettles available.

Nanbu tetsubin – cast iron kettle 

This kettle is for boiling water for tea. It is designed to be used on modern stovetops. The Nanbu Tetsubin (non-affiliated link) features a timeless design called Itome. The Itome pattern is a classic straight line. This tetsubin holds about 40 ounces of fluid, which is enough for tea service for four. 

This kettle will naturally form a patina on the inside with use. The patina is a natural product of oxidation and helps prevent rust and add iron to the water. 

Nanbu tetsubin arare cast iron teapot by Oitomi

This classic Arare cast iron teapot (non-affiliated link) is one of the most beloved teapot designs in Japan. Although this teapot is called a tetsubin, it features an enamel coating on the interior. Therefore, it is suitable only for brewing tea and should not be used on direct heat.

Antique Tetsubin
Antique tetsubin. He’s an old-timer but looks beautiful. A timeless design is one of the benefits of Japanese kettles.

This tetsubin holds just over a liter of water. It distributes heat evenly, and has excellent heat-retention properties. This teapot will keep the tea warm for about an hour, which is perfect sitting in front of the TV watching your favorite show.

Nanbu Reiwa cast iron teapot Set 

This teapot set (non-affiliated link) was designed after the New Gengo Reiwa, which is Japan’s new imperial era. It includes a cast iron teapot and trivet.

The plum petal pattern on the trivet represents the plum blossoms, and the start of the Reiwa era. The teapot has an enamel rust-proof interior. It also has a stainless steel mesh infuser for your loose leaf tea.

Like Oitomi’s other teapots, it has excellent heat retention. So, your tea will stay warm for a long time.

Oitomi Cast Iron Tea Kettles and Teapots – Use & Care

Oitomi’s cast iron products can conceivably last for decades with proper care. So, you won’t have to worry about replacing them if you follow the care instructions. So, it’s important to read any instructions that come with your teapot or kettle to ensure longevity.

How to use an Oitomi teapot
Using a teapot is easy, but there are a few useful tips to get the most out of your teapot. Read on to learn more.

If you have cast iron teapot or kettle, I’ve written a couple of guides that you could find interesting. However, for a quick look, see the instructions below.

Table 3: How To Use An Oitomi Cast Iron Teapot

Before The First UseLet boiling water sit in your teapot for 10 minutes. Tip out and repeat.

This removes odors that may be due to the manufacturing process.
If you’d like, you can add ginger to the hot water.
This will also help remove any odor.

If your teapot is enameled, it’s okay to wipe it out with a soft sponge.
Select your
favorite tea

Since enamel is nonporous and easily washable, it’s okay to mix and match your favorite teas.
However, if you’re not going to wash the inside of your teapot after use.
Then it’s best to use similar types of teas.
Preheat your teapotUnless you are using an Oitomi Cast Iron Tetsubin, you will
need to boil water separately.

If the teapot has an enamel lining on the interior, you cannot boil water in it.

While the water is boiling, warm up the teapot by pouring hot water in it a couple of times.
Let the water sit for a minute and then pour it out. After that, your teapot is dust free and
ready to go.
Brew your tea
Check the packet of tea for brewing times, and enjoy.

After brewing remove the infuser, Otherwise, your tea will over-extract and become bitter 

How to use and care for Oitomi ironware
Cast iron is almost indestructible, but here’s a few tips to ensure your ironware lasts for a long time.

How to clean your Oitomi cast iron teapots and kettles 

I’m a cast iron enthusiast and not a tea expert, so remember to read the instructions for correct use. However, just like other cast iron teapots and kettles, Oitomi’s ironware requires a little care to maintain its durability.

It is easy to care for cast iron teapots and kettles. Just by using your kettle, you are helping to care for it. Regular use helps build up a calcium layer inside of bare iron cast-iron kettle that helps prevent rust, and an actively used kettle will develop its unique characteristic.

Here are some simple care steps to follow for your teapot 

Each time after brewing tea:

  • Empty and rinse out the infuser basket before the tea leaves dry out
  • Make sure you rinse out the teapot
  • Avoid using harsh detergents or cleaners (never use a dishwasher)
  • If the teapot is cold use warm water not hot to prevent enamel from cracking
  • Dry the pot with a soft cloth
  • Turn the teapot upside down to dry completely 

To keep the outside of a lacquered teapot looking shiny and new, soak a soft cloth in green tea. Wipe down the outside and then dry it thoroughly. 

Final Thoughts

Oitomi cast iron teapots and kettles are some of the finest in Japan, and they have both modern, and traditional designs available. They are sold in small teashops to big retailers so be sure to keep an eye for them.

Oitomi teapots
Seasoned cast iron Oitomi teapot

I hope you have found this article useful. Here’s a link to my Japanese cast iron page if you want learn about other Japanese foundries.


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