• HOME >
  • Teapot and Tea Equipment

The taste of water differs depending on how tetsubin is made

[2013.08.29] Posted By

Nanbu Cast Iron Kettle
Many people are aware that a tetsubin effects the taste of water by making it smoother. But, do you know that different brands or different manufacturing method affects the taste remarkably too? I’ve carried out the following experiment to verify the effects of the taste between the different manufacturing processes.

Kamayaki process that affects the performance of a tetsubin

Tetsubin is a cast iron kettle where melted iron is poured into a mold which carries a distinctive design created by the manufacturer. After the casting, the tetsubin is in white-silver color and the tetsubin in this condition gets rusty easily. Thus, the tetsubin is then baked with charcoal fire. This process is called “Kamayaki” which means “firing in a pot”. The term pot refers to a small open kiln. The objective of Kamayaki is to reduce the surface of tetsubin which would prevent it from rusting. The charcoal fire is an unsaturated fire; when the surface of tetsubin is reduced, it will turn into a dark blue color. This process affects the taste a lot. I have requested the tetsubin manufacturer to produce a tetsubin according to my parameter and study the relationship with the taste of water.

Tetsubin before Kamayaki

Tetsubin Before Kamayaki

Tetsubin After Kamayaki

Tetsubin After Kamayaki

  1. Tetsubin without Kamayaki
  2. Tetsubin with twice as long Kamayaki as standard

I have compared the taste of water boiled in the above tetsubin versus a normal tetsubin. We used hard charcoal for the experiment.

The results are as follow:

  1. The tetsubin without Kamayaki noticeably increases body and after taste. The performance of this model in terms of the water taste was the best among 3 tetsubins.
  2. The tetsubin baked twice as long as ordinary tetsubin does not make the taste of water smooth at all. The intensity of the after taste was more or less the same as stainless steel kettle. However, the body was weaker than that of stainless steel electric kettle.
  3. Kamayaki reduced the body of water regardless of the processing time

Non-Kamayaki produces the best result in terms of the taste

Based on the above experiment, I am affirm that the Kamayaki process affects the performance of a tetsubin. Ironically, the non-Kamayaki tetsubin produces strongest body and after taste, however, there is a downside as it is so easy to get rusty, so fast that it started rusting while I was using it. Since it gets rusty no matter how we use it, it is somehow not practical.

The Kamayaki may affect the surface structure of tetsubin

We found that the longer the Kamayaki is carried out, the lower the performance of tetsubin will be. I assume that it has something to do with the surface structure of tetsubin. Moreover, the inverse proportion between firing temperature and the performance was also observed using clay teapot. The higher firing temperature melts down the mineral granule and decreases the surface area. A tetsubin has more a complex and larger surface area as compared to the normal iron. Using the same theory, I would assume the reason for the decrease in performance after undergoing longer firing or higher baking temperature would be due to the melt-down of the particles and also, resulting in a decrease in surface area of tetsubin.

The type of charcoal used for Kamayaki affects the taste

Based on my investigation, I noticed that different brands of tetsubin use different types of charcoal where some would use hard charcoal and some soft charcoal. The firing temperature of hard charcoal is higher. If we just judge based on the taste, it would be more ideal to use soft charcoal.

Satetsu Tetsubin

Have you heard of “satetsu tetsubin”? Satetsu means sand-iron in English. Although the material used for satetsu tetsubin is not the same among the different manufacturers, the essential point is a satetsu tetsubin does not undergo the Kamayaki process. Originally, satetsu iron has higher density where it is said that the rust is unable to penetrate into the iron structure. Therefore, the satetsu tetsubin produces a very strong body and after taste. Long ago, I used to think that the satetsu tetsubin performed great due to its material. But for now, I believe that the main reason for a satetsu tetsubin to perform well is because there was no Kamayaki process performed. However, the satetsu material is very brittle. It may crack with a small mistake in handling which normal cast iron kettle would not.

satetsu tetsubin

satetsu tetsubin 0.9L

Related Articles

How to get the latest update on HOJO Tea?

1. Follow Twitter, 2. Click "Like" on Facebook, and 3. Subscribe in newsletter. You can have the latest tea news from HOJO Tea.

Subscribe the Newsletter to enjoy the privileges
You may receive a free sample upon purchase, or you may have the priority to purchase special products. So please remember to subscribe our newsletter as well as the social network.
  •                 

HOJO TEA Online Shop NEWSlist

We have released the Flower of Ancient Tea Tree
We have released the Flower of Ancient Tea Tree. This is the fresh tea flowers hand-picked from old tea trees of ancient tea gardens. The tea garden is totally sustainable, with natural farming practice and no pesticide or fertilizer at all. The tea garden is located at altitude of 2000-2200m in the western part of …
Limited Sales of Single Tree Raw Pu-erh,White and Black tea 2019
We have released Single Tree Pu-erh Tea 2019. Literally, the single tree tea is harvested and processed only from one single tea tree. Each single tree tea is sourced from the high mountain in west Lincang, the altitude is at around 2000-2200m. Thick Taste of Old Tree We selected particularly old tea tree for making …

NEW ARTICLES

We have released the Flower of Ancient Tea Tree
We have released the Flower of Ancient Tea Tree. This is the fresh tea flowers hand-picked from old tea trees of ancient tea gardens. The tea garden is totally sustainable, with natural farming practice and no pesticide or fertilizer at all. The tea garden is located at altitude of 2000-2200m in the western part of …
Limited Sales of Single Tree Raw Pu-erh,White and Black tea 2019
We have released Single Tree Pu-erh Tea 2019. Literally, the single tree tea is harvested and processed only from one single tea tree. Each single tree tea is sourced from the high mountain in west Lincang, the altitude is at around 2000-2200m. Thick Taste of Old Tree We selected particularly old tea tree for making …
Lapsang Souchong Qi Zhong from Tong Mu Guan in Wuyi Mountain
We have released Lapsang Souchong Qi Zhong. It is the most premium Lapsang Souchong in HOJO’s line-up. This tea is from Tong Mu Guan in Wuyi Mountain. Qi Zhong is seed-grown tea tree, and tea garden is totally sustainable. Unlike ordinary black tea, this unique black tea gives strong fruity flavor  reminiscent of peaches and …
Amazing difference between seedling tea and cultivated tea
Do you know that tea is divided into two groups: cultivated tea propagated by cuttings, and seedling tea grown from seed?There is actually a big difference between cultivated tea and seedling tea. What is Cultivar? The cultivated tea refers to tea with a name of specific cultivar, such as Yabukita, Benifuki, Okumidori, Tie Guan Yin, …
Da Cha Lin Raw Pu-erh Tea 2019 is available in our store
We have released two types of unique raw pu-erh tea, Da Cha Lin Raw Pu-erh Tea and Da Cha Lin Purple Tea. Da Cha Lin means the forest of huge tea tree. Literally, Da Cha Lin is made from huge ancient tea trees which supposed to be processed for single tree tea. It gives outstandingly …
Limited Release of Special Taiwan Oolong Tea
In 2019, we bought three types of special Taiwan oolong tea in addition to our standard line-ups. These teas are the limited tea since we may not be able to get the same quality tea every year. Introducing the unique tea as a special grade Every year we visit Taiwan and conduct tea tasting to …
New Release of Bai Yan Shan High Mountain Raw Pu-erh Tea
We released Bai Yan Shan High Mountain Raw Pu-erh Tea. This tea was produced from tea garden located at about 2300m. The garden has gone completely wild since it has left unattended for decades. Tea garden that altitude is at 2300m In Chinese, Bai Yan Shan means White Rock Mountain. It is located in the …
Limited Release of Single Tree Purple Tea
Now Single Tree Raw Pu-erh Tea of Purple Tea is available in both Japan and Malaysia. In China, single tree is called Dan Zhu. It means tea is distinctively made from one particular tea tree. Since the old tree of purple tea is very limited, we have only very limited stock. The old Tree of …

PAGETOP