Japanese cast iron teapot vs kettle. What’s the difference?

Teapot or kettle or teapot kettle whats the difference?

If you enjoy a nice cup of tea, then you may have heard that using old-fashioned, cast-iron teapots and kettles is a great way to make that perfect cuppa. In Japan, many people enjoy making their tea in traditional cast iron teapots and kettles called tetsubins. But do you know the difference between the two vessels? In this article, you can learn the difference between a Japanese cast-iron teapot and kettle.

Table of contents

  1. Trust and expertise
  2. Features of a cast-iron kettle
  3. What do kettles look like?
  4. Using a traditional kettle in premodern Japan
  5. What is a cast-iron teapot?
  6. Features of a cast-iron teapot
  7. What do Japanese teapots look like?
  8. Cast iron teapot vs. kettle
  9. Dual-purpose teapot/kettle
  10. Benefits between teapots and kettles
  11. Summary

Trust and expertise

Better yet, if you believe the Japanese, ironware is a healthy way to make tea. Because, they say iron purifies water, enhances flavor, and adds iron.

To be honest, I can’t say I’m a tea expert. However, I have lived in Japan for 17 years and collect cast-iron, including Japanese ironware.

And I have also visited cast iron foundries around Japan with many in Iwate.

Iwate is a well-known region for making cast iron products called Nanbu Tekki or Nambu Tekkei, depending on translation.

Also, I have an interest in history, especially the history of the 1800s. At the same time, that many Japanese iron smelters started selling their wares.
Cast-Iron Teapot or Kettle?
Which would you choose, a teapot or kettle?

Cast iron enhances the flavor of your tea

With this knowledge, I hope to introduce you to Japanese teapots and kettles. How to distinguish them and how they are used.

But if you prefer to learn how to use your teapot, then click the link to read the step by step guide. With that being said let’s get started.

What is the difference between a cast iron teapot and a kettle?

Japanese kettle also known as a tetsubin

Cast-iron kettle features

  • Japanese kettles are to boil water for your tea and not for steeping
  • Kettles tend to be larger than cast-iron teapots, and hold a larger capacity of water
  • Traditionally kettles lack an enamel lining and the interior is raw iron
  • Do not come with a tea strainer

Since cast iron kettles don’t have an enamel lining. Some kettles could be suitable for use on direct heat source such as a fireplace and even over flame. However, I recommend you check with the retailer you purchase from. Just to be on the safe side.

What do Japanese kettles look like?

  • Japanese cast iron kettles come in a variety of shapes and sizes
  • Usually older kettles hold over a quart of water. However, modern kettles tend be smaller
  • Modern tetsubins usually have a simple exterior with little patterning
  • Some have simple pictures on the exterior. Such as horses and mountains
  • Have a dull gray interior or a calcified white layer over the iron

Antique Japanese kettles

Early Japanese tea kettles were very heavy pots and much larger than the ones you are likely to see today. Back then the Japanese used an indoor hearth called an Iori. A tetsubin hanging over an Iori would have been a common feature in Japanese homes. The Iori was used to cook and a way to warm their homes prior to electricity.

Hanging a cast iron kettle over an Iori served two purposes:

  1. Hanging a tea kettle over the fire would mean there was always hot water available
  2. The steam would humidify the room; indoor fires makes the air extremely dry

Although Japanese heat their homes using modern technology. It still not uncommon to see a kettle on a heater to humidify the room, especially in public schools. And if you have a fireplace, you may want to use a tetsubin in winter to humidify the room and have hot water, ready anytime you feel like a cup of tea.

A traditional Japanese hearth
An open fire was once common in Japanese homes. This reproduction has an earthenware bowl hanging on a hook. By the 18th century this pot would most likely be replaced by a cast iron kettle called a Tetsubin. This Iori is located at Mahoron Shirakawa Fukushima.

What is a cast iron teapot? (Kyusu)

Cast iron teapots and kettles look similar, but teapots are smaller and have enamel on the inside. This is to prevent rust. It is important to remember not to use a teapot on a stove or over an open fire.

Cast iron teapots are for brewing or steeping tea, not for boiling water. If boil water with a cast-iron teapot, the enamel may chip or craze (develop fine cracks). Whatever you do, don’t use your enamel teapot on your stove.

Cast-iron teapot features

  • Usually teapots hold less than a quart of water
  • Most cast-iron teapots are lined with enamel to prevent rusting
  • Most Japanese cast-iron teapots will come with a tea-infuser
  • Many teapots will have an unfixed handle that can fold down for storage

Cast iron teapots are designed to steep tea and not to boil water. And most come with an enamel lining, this enamel prevents rusting and makes your teapot easy to clean.

What do Japanese teapots look like?

  • Cast-iron teapot come in a range of colors and sizes
  • Available in both modern and traditional design
  • Handles placed over the teapot for easy pouring

The use of cast-pots has become popular in Japan. Teapots come in many sizes and colors, but the brightly colored, single-serve teapots are commonplace among Japanese office workers.

Learn about Japanese cast iron teapots
Cute little cast-iron teapot made by Iwachu.

Today cast iron teapots are more popular than cast iron kettles

You could argue that Japanese enameled teapots are not part of traditional Japanese culture since the technique of enameling came from the West. And Japanese would traditionally have used a ceramic clay teapot.

However, today you are more likely to find a cast iron teapot in a Japanese house than a cast iron tea kettle. I’ve written an article on some of the best cast-iron teapots. If you’re interested, just click the link.

Japanese tea kettle vs teapot infographic
Which is your perfect pot a teapot or kettle?

Cast iron teapot vs cast iron kettle

  1. Apart from the enamel inside the teapot, there are two simple ways to distinguish them: kettles generally hold more water. And some hold up to two quarts (about two liters) of water, whereas most teapots hold between 300-500 milliliters.
  2. Many Japanese teapots come with a tea infuser that fits snugly into the pot. While a traditional kettle will most likely not with a tea infuser.

Is there is a hybrid teapot kettle?

While kettles and teapots are for different purposes, there are hybrid versions available. With these teapots, you can use one vessel to boil water and to brew your tea.

These hybrids are lacquered or seasoned on the inside to prevent rust. But unlike enameled teapots, the flexible coating does not crack or craze. In general, they look more like traditional seasoned cast-iron.

Some seasoned teapots are not IH compatible. So I would recommend to check with the retailer before purchasing.

Cast iron teapot, kettle or hybrid. Which one is right for you?

Now that you know the differences between cast iron kettles and teapots. The next question you might ask is, “Should I buy a kettle, teapot, or a fusion between the two?”

I recommend choosing a standard enameled teapot for your first purchase. Out of the three choices, I think you’ll get the most use out of a regular cast-iron teapot. And because of the enamel lining, it will be easy to clean and maintain.

Table: Comparison table, between cast iron kettles, teapots and dual-purpose teapots

Cast-Iron Kettle
Enameled TeapotSeasoned Teapot

Boil waterSteep teaBoil water
Steep tea


Raw ironEnamel liningPolymerized oil

Not requiredHand wash
(easy clean interior)
Hand wash
(sponge only)



Cast iron teapots and kettles are durable, beautiful tea vessels. You can use them on special occasions and for everyday use. Many people enjoy these teapots as a comforting part of a nightly routine. However, it’s useful to know the difference between cast iron teapots and kettles. Otherwise, you may inadvertently damage your teapot.

This reminds me, if you want to know how to care for your cast iron kettle, then this article covers a lot of the questions you may have.



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