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.

Here’s why Oitomi is a great choice. 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 which will last for many years.

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

I was very 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.

Table of information on Oitomi

Oitomi origins Oitomi is based in the Iwate prefecture which is the cultural
center for cast iron manufacturing in Japan, dating back over
900 years.
Oitomi was founded in 1848 by the Oikawa family which
also founded the Oigen foundry nearby.
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 to met high Japanese

Oitomi also recycles iron onsite that is sourced from within
Japan such as building and bridge girders. Products that
don’t met their quality control are also 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 tradition 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.

Because of their casting expertise, they also partner with
different industries such, as the sound industry.
Oitomi worker checking a sand mold
Sand molds are carefully checked.

Background and history of Oitomi

The Japanese company Oitomi was established in 1848 in Oshu City, in the Iwate region of Japan. It is one of the oldest workshops in the Southern Iwate Prefecture. They are famous for their cast iron kettles and teapots but they also make a variety of cookware and wind-chimes. If you want to learn more about Nanbu Tekki here’s an interesting article.

Foundry working demonstrating sand casting methods
Keeping traditions. A foundry worker in Oshu Japan teaching members of the community about the local casting industry.

For over 170 years, Oitomi has remained in the capable hands of the Oikawa family which also operates the sister company called Oigen. I’ve written an article on Oigen, click the link if you’re interested in seeing some beautiful kettles. 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 choice from over 2000 molds. From design to manufacture it’s all done on-sight and finished to the client’s specifications. That could one of the reasons why Oitomi’s been in business for over 170 years.

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

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

As you enter the foundry you are surrounded by the
essential ingredients 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 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, however, teapots are enameled
before its final rust prevention coating.

Either a traditional high gloss lacquer is applied called
Urushi or oil is polymerized into the iron in a similar way
you may season your pan at home.
Smoothing cast iron cups
Each piece of cast iron is inspected for imperfections and rough edges smoothed.

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 tea 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 accessories for tea service. Here are a few of their offerings

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 a 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 directly overheat.

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 for after-dinner tea service. 

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 of the trivet represents the plum blossoms of Manyoshu, which is the source of Reiwa. The crisp cocoon pattern of the teapot is representative of the blossoming flower of the Manyoshu. 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. This teapot is not for use over an open or direct flame.

Oitomi Cast Iron Tea Kettles and Teapots – Use & Care

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

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

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

Table 3: How To Use An Oitomi Cast Iron Teapot

Before The First UseTo get started, you’ll need to boil water. If you are using an
Oitomi Tetsubin that is suitable for boiling water, you can
simply boil the water and tip it out and then your Tetsubin
is ready for use.

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

As for your teapot just give it a good rinse water warm
water and 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 washed it’s okay to
mix and match your favorite teas. However, if your not
going to wash the inside of your teapot 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
water in it a couple of times. Let the water sit for a minute
and then pour it out. After that you teapot is clean and
ready to go.
Brew your tea
Check the back of your packet of tea for brewing times.

As for the brewing correct temperature to boil your water?
That sounds like fancy marketing, just boil the water and enjoy your cuppa.

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

How to clean your Oitomi cast iron teapots and kettles 

I’m a cast iron enthusiast and not an expert on tea 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 own 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 kettle or 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 a traditional designs available. They are sold in small teashops to big retailer so be sure to keep an eye for them. What better why to enjoy your tea than in a traditional cast iron teapot.

Oitomi teapots
Seasoned cast iron Oitomi teapot

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


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