What are Tetsubin? 10 Things to Know About Cast Iron Kettles

by Anne Walther | CRAFT

© Hibachiya / Creative Commons, Tetsubin Kettle

If you’ve ever had tea in Japan, you’ll know how delicious it is. But why is it so difficult to recreate that flavor when you get home? It’s not just the tea leaves you need to think about, but also the other tools you’re using. Bowls, spoons, and even the environment are all important factors, but perhaps the most essential component is the tetsubin, or cast-iron kettle.

Why are tetsubin so essential for Japanese tea, and how can you choose the right one? Let’s take a look!

Contents

1. What is a Tetsubin?
2. The History of Tetsubin
3. Why are Tetsubin so Important?
4. What’s the Difference between Tetsubin and Other Types of Japanese Kettles?
5. Tetsubin or Tetsukyusu?
6. Where are Tetsubin Made?
7. How is a Tetsubin Made?
8. How to Use a Tetsubin?
9. How to Brew Tea in a Tetsukyusu?
10. How to Take Care of Your Japanese Cast Iron Kettle or Teapot?

1. What is a Tetsubin?

© Morioka Study Museum of Archeological Site, Fuji-Shaped Tetsubin

Tetsubin are Japanese cast iron kettles equipped with a top handle, a lid, and a pouring spout. They are used for boiling hot water, especially for making tea. The name tetsubin (鉄瓶) literally means iron pot.

In the Japanese art of chanoyu (tea ceremony), tetsubin are placed on a portable brazier named binkake (瓶掛) and traditionally heated over charcoal. Often elaborately decorated with relief designs on the outside, tetsubin may have various and sometimes unusual shapes. They usually contain between 0.5 and 5 litres (16.9 and 169 oz) of water.

Cast iron is believed to enrich and improve the taste of boiled water. As Japanese teas are refined and delicate, the tea’s after-taste becomes sweeter and rounder when the water is boiled in a cast iron kettle. In addition, thanks to the iron content of the tetsubin, the tea water provides further health benefits.

2. The History of Tetsubin Kettles

© Suzuki Shuzendo, Tetsubin Design and Pattern Books

The origin of the tetsubin is still not completely clear. The Japanese Illustrated Encyclopedia of The Way of Tea (Genshoku Chado Daijiten), states that the tetsubin developed from a water kettle named tedorigama (手取釜) (sometimes also spelled tedorikama). The latter was already being used in in the sixteenth century.

Another hypothesis is that the popularity of the tetsubin grew with the spread of sencha, Japanese loose leaf green tea. During the Edo period, in the second half of the seventeenth century, Chinese merchants visiting Nagasaki brought loose leaf tea knowledge to Japan. At that time, Japanese intellectuals were strongly inspired by China, enjoying Chinese arts and crafts.

© Tokyo National Museum, Senchado Tea Set

Senchado, the way of sencha, spread from the eighteenth century until the beginning of the Meiji era. People that enjoyed this practice were mainly educated merchants who started drinking sencha in a less formal atmosphere than in chanoyu.

For common Japanese households, Chinese tea utensils used in senchado remained scarce and luxurious. Consequently, new Japanese kettles were used, and this led to the increasing popularity of tetsubin. The latter soon became an important domestic utensil for tea preparation.

During the nineteenth century, tetsubin designs went from uncomplicated iron kettles to elaborately engraved works of art. A tetsubin’s degree of finishing indicated the wealth of its owner, and thus could be appreciated as a status symbol.

3. Why are Tetsubin so Important in the Tea Ceremony?

© Suzuki Shuzendo, Jujube-shaped Tetsubin

Although the use of the tetsubin originally developed with the spread of senchado, it still has an essential function in chanoyu (tea ceremony with matcha preparation).

In ryakubon, the first ritual preparation a chanoyu host learns, a tetsubin is used to boil water for preparing tea. When the tea ceremony is held outdoors, a tetsubin may be used instead of a kama (round or cylindrical kettle with lugs for inserting metal handles). Portative, small, and equipped with a spout, the tetsubin is sometimes preferred because it is more convenient.

Tea Ceremony by Mizuno Toshikata, c. 1900

The ornamentation and forms of tetsubin are delightful in their simplicity. Not only are they aesthetically pleasing, but they also embody ichi-go ichi-e (“for this time only” or “once in a lifetime”), a concept of Japanese culture that captures the essence of the present moment shared by fellow tea friends. As tetsubin are passed on from one generation to the next, they acquire patina and may be related to the philosophy of wabi-sabi (What is Wabi-Sabi?). In contrast to contemporary over-consumption, wabi-sabi encourages simplicity and authenticity in everything.

To find out about the other tools of a Japanese tea ceremony, take a look at these 19 Essential Japanese Tea Ceremony Utensils.

4. What’s the Difference between Tetsubin and Other Types of Japanese Kettles?

© Ashiyagama no Sato, Muromachi Period Kettle

The shape of the tetsubin shape was probably inspired by other kettles at that time, which include: dobin, the mizusosogi, the tedorigama, the toyama (a sake warmer), and the yakkan.

Large teapots with a bamboo, wicker, or wooden handle on the top, dobin were used to boil water and to brew tea or herbal teas. They are usually made of ceramic and common in Japanese households.

© Yasunari Nakamura / Creative Commons, Yakkan

The yakkan is the closest in design to the tetsubin. Nevertheless, the yakkan is made from copper, whereas tetsubin are traditionally made of cast iron. It is often stated that water boiled in an iron kettle and water heated in a copper container have different tastes.

Another interesting feature about the tetsubin is that the ornamented side is generally the one with the spout facing to the right. The reason for this is that in senchado (tea ceremony with loose leaf green tea), the tetsubin is held with the right hand. In chanoyu (tea ceremony with powdered green tea), it is carried with the left hand. The yakkan is also held in the right hand, showing further proof that the tetsubin and yakkan are closely related.

5. Tetsubin or Tetsukyusu?

© Jérémie Pouchard / Creative Commons, Japanese Tea Ceremony Set

Outside Japan and especially in the Western market, the most famous Japanese teapot is the tetsukyusu (鉄急須) (iron teapot), a cast iron teapot that outwardly looks like a tetsubin.

Nevertheless, there is a major difference: the inside of the tetsukyusu is glazed with enamel to make it more practical for tea brewing and is often equipped with a removable tea strainer. Tetsukyusu cannot be used to heat water because this would irremediably damage the enamel coating inside.

© Noodle Kimm, Tetsukyusu in a Shop Window

Although these expressions are now often employed interchangeably, a tetsubin is not to be confused with a tetsukyusu. The latter is only used for brewing tea, but not for boiling water. A tetsubin is needed for boiling water, but not for brewing tea.

Have a look at your cast iron teapot: if the inside is enamel glazed and equipped with a strainer, it is a tetsukyusu!

In the 20th and 21st centuries, many cast iron tetsukyusu appeared in the overseas and online markets. Most of them are crafted by factories in Japan or sometimes even in China, at an extremely low cost. Be careful and focus on craftsmanship and quality! To find out more about shopping for Japanese teapots check out Kyusu: Choosing the Best Traditional Japanese Teapot.

6. Where are Japanese Tetsubin Made?

The region of Tohoku is best known for producing tetsubin and tetsukyusu. Previously employed to create weapons, iron casters settled in the Tohoku region of Japan. In this area, the local daimyo had a strong affinity for tea culture and actively promoted cast iron craftsmanship. He even invited famous iron casters to settle down in the castle town. Moreover, the Tohoku region was rich in wood and natural iron.

The cities of Morioka, Mizusawa (both located in Iwate prefecture), and Yamagata (in Yamagata prefecture) are the most famous for cast iron ware. Morioka and Mizusawa production are known as nanbu tekki (南部鉄器 - southern iron utensils). While Mizusawa produces kitchen ware for everyday use, Morioka specializes in high-level tea ware. Yamagata manufactures cast iron qualitative wares in a simpler style.

Founded in 1902 in Iwate prefecture, Iwachu is one of the leading Japanese manufacturers of tetsubin and tetsukyusu. Each of them bears a "Made in Japan" logo and the Iwachu symbol engraved as a guarantee of quality and genuine origin.

Kyoto was also once known for iron ware production with a different design: a simple sanded surface, solid carving, and sometimes silver inlays. Nevertheless, this production does not exist anymore. Some Yamagata cast iron tetsubin still feature silver inlays, as a vestige of the late Kyoto style.

If you’re planning a trip to visit some of these locations, you should also check out The A-Z of Japanese Pottery: 32 Most Popular Ceramic Styles.

7. How is a Tetsubin Made?

Cast iron kettles and teapots are produced by pouring molten iron into either clay or sand molds. Clay molds are usually employed in the production of high-quality artisanal tetsubin. For high-end Japanese cast iron kettles, the mold is used only once. In this case, the stamping work is manually performed on each kettle. Sand molds are generally used for mass production, especially for export. Yamagata tetsubin are sometimes produced using metal dry molds.

Once the tetsubin is shaped, its pattern is stamped. There are three major traditional patterns. The most famous is probably the arare dotted pattern. The sharpness of arare depends on the iron caster’s craftsmanship, as well as how many times the same mold is reused.

Arare (霰) means hail or hailstones in Japanese. There are various sizes of dots; the biggest pattern is named oni-arare (鬼霰), oni meaning ogre. Another pattern is hada (肌 skin), a rough surface with irregular texture. The last traditional motif is figurative. It can be a depiction of birds, flowers, horses, landscape, or plants.

8. How to Use a Tetsubin?

Firstly, rinse your tetsubin with cool water after purchase, then boil water inside several times to clean it.

Tetsubin can be used over gas stoves or open fire. Do not use them on electric stoves. Once the water boils, carefully slide the lid open using a towel to avoid getting burned.

9. How to Brew Tea in a Tetsukyusu?

© Eduardo Froza, Tetsukyusu with Strainer

As tetsukyusu are well-known in the Western market, we thought it would be useful to share some tips to take care of your Japanese teapot. The steps below are specific to tetsukyusu, cast iron teapots with tea strainer and enamel coating inside. Tetsukyusu should never be used over a fire.

Firstly, rinse your tetsukyusu using hot water. Fill the tea strainer with tea without overpacking it. The tea leaves should have enough space to expand. Pour hot water into the teapot and steep your tea. Remove the strainer with tea once it has brewed. Repeat brews if you wish.

10. How to Take Care of Your Japanese Cast Iron Kettle or Teapot?

Please refrain from pouring cold water into a tetsubin or tetsukyusu that has just had hot water in it, or that is still hot. This may cause possible cracking and damage.

Always empty your tetsubin or tetsukyusu when not in use. Rinse it with warm water and dry immediately after use with a dry cloth, to prevent rusting. Let it dry in a ventilated place. If storing away, make sure that the inside is dry. As with any teapot, refrain from using any soap or detergent.

We wish you lots of fun with your Japanese cast iron kettle or teapot!