Sunday, April 3, 2011

Harmonizing Water and Tea: Part 6- A Look At Silver, Ceramic, and Iron Kettles and Tetsubins

The type of kettle or tetsubin used to boil the water for tea has a profound effect on the water and therefore on the resulting infusion. There are only two moments during the preparation of tea where three of the Five Elements directly interact- while boiling the water and while steeping the tea. The boiling of the water is more yin and the steeping of tea is more yang. In the most basic sense they comprise a whole and result in the final product of tea.

These two instances are the points in tea preparation where there is the strongest exchange of energy. So in many ways these two points have a very strong relationship with timing (astrology) because over exposure to one of the three elements will create unequal balance and lead to inferior cup of tea.

The elements that deal with the boiling of water are Water and Fire. Water pertains to the water (of course) and Fire pertains to the heat source. Between them in the cycle of elements is either Earth or Metal- the materials of the kettle or tetsubin. Earth and Metal also lay between the water and the heat source when preparing tea. As such the interactions between these elements should be carefully considered when trying to harmonize water with tea. Metal is thought to strengthen Water (producing cycle) and Earth is though to moderate it (controlling cycle).

Silver is the colour white and is absolutely lustrous, this makes it the purist of all metals. It is light in nature and is therefore full of yang energy. In the cycle of elements Metal is thought to empower Water. The pure light energy of silver does just that. Much has been written about the benefits a sliver kettle and its effects on water throughout history and even on the blogasphere (See Marshal'N posts on silver, Stephane's post on silver and this wonderful article by Aaron Fisher). Even the Saint of Tea, Lu Yu, recommended its use (as discussed here in the bookclub) and the Japanese mastered the art, some of the most well made come from here.

Silver strengthens water because it is the purest metal. Silver imbues water with a light quality because silver is light in nature. It sweetens water because silver has strong yang qualities- it is light, shiny, and pure. The sweet flavour is yang in nature and is thought to strengthen. Silver is a sign of purity. Not only does it purify the water but also it helps cultivate the pure mind of those who boil water with it (In Steve Owyoung's translation of Lu Yu here).

Water boiled in silver kettles harmonize best with lighter teas such as white tea, green tea, and lighter oolong. The water boiled with a silver kettle doesn't restrain the light rising energy of these teas and augments their subtle, light nature. Silver kettles bring out more yang characteristics such as smells and sweet subtle tastes, qualities that are prized in these types of teas.

The downsides of silver is that it cannot withstand long periods of high temperatures and although it conducts heat quickly, it also looses heat relatively quickly. Silver can easily tarnish just as a pure mind can be corrupted. Silver is a very luxurious metal and should be only used for special occasions and for special guests otherwise it can impart those who prepare tea with pretentious attitude.

Ceramic kettles are composed of earth and carry with it the qualities of Earth. Earth is thought to carry harmonious, balancing, and neutralizing properties that are neither yin nor yang in nature. Water springs forth from the earth and therefore has a close relationship with it. Earth is thought to control Water, afterall, the rocks of the mountain once contained waters true nature. Reuniting water with earth helps to bring it stability, thereby strengthening the connection to its original nature. There are a growing number of tea bloggers out there that are using ceramic or clay kettles/tetsubins such as David and Phillipe, who use Taiwanese based Lin's ceramic kettles, Imen, who uses a Chao Zhou style kettle, and Stepahane, who has experimented with a zisha kettle, and the author of MattCha's who uses a Korean style ceramic tang gwan. Traditionally places such as Hangzhou (see Steve's Comment) and much of Chao Zhou (Teamasters Blog and Tea Obsession) in China, Korea (MattCha's Blog), and even Japan (Gongfu Girl) have used such kettles.

Ceramics harmonize water rounding the bad edges of the water and augmenting the good. This is the function of Earth- keeping things in harmony and balance. If the water has manged to pickup strange odours and tastes, a ceramic kettle will round off these unpleasant characteristics. The porous nature of clay acts as a sponge and filter- removing these undesirable qualities. On the other hand, if the water is flat and lacks vitality, a ceramic kettle will regenerate the lost vitality. The exchange of minerals, substances, and energy of the clay will leach into the water. If the water is too heavy with a mineral content that is too high, it will remove some of its weight. Conversely, if the water is too light with a mineral content that is too low, it will augment the water with weight. In this way Earth is said to control Water by bringing it closer to its true natural state, the way it was when resting amongst the earth and rocks before it was extracted.

Earth is grounding and centering in nature. Not only does it even out the water but also it helps ground and center the minds of those who boil water with it, cultivating the Middle Way. Boiling water from a ceramic kettle can also connect us to nature.

Water boiled in ceramic kettles harmonize best with most teas. Almost all tea will benefit from the harmonious nature of water boiled in ceramic kettles. Very deep dark teas such as aged high quality puerh and very light subtle teas such as first pick, early spring, premium quality green teas are best not brewed using water from a ceramic kettle. This is because the water from a ceramic kettle has subtle moderating properties, centering the deep yin nature of an old puerh and the light yang nature of the lightest greens. Earth is moderating in nature. This is only for the purest of tea though, most old puerh and early spring green will actually benefit from water boiling in a ceramic kettle.

The downside of ceramic kettles is that they can easily break if care is not taken. In this way, they cultivate a mindful practice when preparing tea.

Iron is a deep lustrous grey colour and is quite heavy. These deep, heavy characteristics give iron a strong yin, sinking quality. Metal is thought to empower Water. The heavy, deep nature of iron does just that. Its deep yin nature strengthens the true yin nature of water. Iron gives water a certain full, round quality to it- a diffuse, subtle, or deep sweetness is also added to the water. It makes water more heavy in the mouth with an enhanced mouthfeel. Deep full flavours are yin in nature. There is still some diffuse deep sweet tastes (yin within yang) because Metal strengthens Water. Iron tetsubins are very durable and often reasonably priced which makes them practical. Many tea bloggers use iron tetsubins (Hobbes, Stephane, Marshal'N, Zero The Hero, Aaron Fisher, Toki). They follow good company as Lu Yu must have appreciated these characteristics because he also used a iron tetsubin and reccomended its use for everyday tea.

Iron is also a relatively reactive substance, infusing the water with minerals (see HoJo's thorough article here). Water boiled in iron therefore carries some of this element into the body. Because iron is heavy in nature, water boiled in an iron tetsubin sinks to the deepest levels of the body. It is even said that iron can reach the deepest, blood level of our body (deep yin), nurturing it. This is how iron is strengthening. It literally strengthens our blood of which iron (and oxygen, its yang component) is a major component. Iron is therefore said to be strong and enduring in nature. Not only does it strengthen the water but also helps cultivate strength and mental endurance of those who boil water with it. The heavy nature of iron is thought to suppress elevated moods, emotional outbursts, tempers, and other boisterous behaviors. These states of mind should be reined in during the calm mindfulness of a tea session. Water boiled in an iron tetsubin helps bring us down, into the moment with tea.

Water boiled in iron tetsubins harmonize best with darker, deeper teas such as red tea, black tea, darker oolong, and puerh tea. The water boiled with an iron tetsubin sinks harmoniously to the deeper levels with these teas, guiding them deeper, and augmenting their deep, rich nature while sweetening them slightly. Iron tetsubins bring out more yin characteristics such as deep, rich, full tastes and mouthfeel qualities that are prized in these types of tea.

The downside of iron tetsubins is that they can easily rust. Even strong minds can waver, if they are careless. Iron is also very heavy in weight especially when full of water. Those who are weak can be overwhelmed by the heavy weight of these tetsubins. This can lead to jerky movements restricting of the qi of the person preparing tea and interrupting the smooth flow and ease of interaction in the tea room.

The next part will look modern issues with the kettle/tetsubin and other factors that should be considered when using a kettle/ tetsubin to harmonize water with tea.



Philippe de Bordeaux filipek said...

Very interesting Matt,

Thank You .

It's very important for tea leaves good and apropriet water...

See You later.

Best regards.

. Philippe .

Matt said...


Thanks for your interest. Matching the appropriate water to the right tea will always give you the best results. This is just as true for the vessel you boil water in.

Thanks for stopping by.


Matt said...


One enjoyed your excellent posts on your ceramic kettle here:

and here:

but didn't know where to hyper link them into the body of the post :D


David said...

Great article Matt !

I've been talking to Akira about kettle issues. He is rather specific on the subject and opened my eyes on a lot of things. Thanks to his guidance, I've been doing some tests lately, which help me understand more on the subject.

I still have to try one day a tetsubin and, if I can, a silver kettle, but about the clay kettles, as I also own a Lin's ceramics kettle, I cannot agree more with what you say.

Your water and tea section is really great. It is worth reading, and reading back again and again.

Matt said...


This post is very general. As you mentioned, the more time you spend with certain type of kettles/ tetsubins, the more you will find individual characteristics that pop out amongst these general types. For example, within the category of ceramic kettles/tetsubins, there may be some that add more light sweet qualities and some that add more depth with the same tea and water with all other variables held constant.

This is the never-ending marvel of the Way of Tea!

Akira's article is one of the most thorough on the topic of iron tetsubins in English. It goes into some of the factors effecting the water boiled in iron tetsubins with great detail. See here:

Tried to find an article about your Lin's ceramic kettle but couldn't find one yet! ;)


Julien ÉLIE said...


didn't know where to hyper link them into the body of the post

Maybe by adding a sentence in the appropriate section about ceramic kettles (you already mentioned Many tea bloggers use iron tetsubins (Hobbes, Stéphane, Marshal'N, Zero The Hero, Aaron Fisher), so a similar pointer to Philippe's articles, David's and others could be done…}.

Thanks again for your very interesting article.

Incidentally, you did not speak about stainless steel kettles… Metal element! :-)

Regarding iron, I still have doubts about its being healthy for all people. Too many iron may not be safe, and water may be too heavy. And if above all, the kettle is rusty, it may trigger other health issues off. Of course it will not harm everyone, and it depends on the tetsubin. Yet, it should be taken into account.

David said...

For your information, Akira is in the process of writing a 30 pages document on water only. I had the chance to read one extract and it is going to be really sharp. I can't wait to read it. I think it will raise some new questions in the tea community, even sound too extreme by some.

About Lin's kettle, Philippe has already done a beautiful job on the subject as you mentioned. As a matter of fact, tonight I tried a beautiful dan cong the way it is often drunk in Guang Dong : 10g in a 12cl gaiwan.

I did more than 30 brews with a friend, half of them using water from my stainless kettle (inox), the other half using (the same) water from the Lin's. The difference appears much clearer to me now.

Lin's kettle water is sweeter leading to a less dry tea. It is usually a good thing but not necessarily with every tea. With some oolong, it can hide citrus notes for example. But the result is really smart and pleasant.

I've been wondering for a while if it adds length in the after taste or not. I think it does, but I had the chance to drink wonderful dan congs lately which are already very long, so it is not easy to be sure.

Maybe Philippe could add some of his findings if he wishes.

Matt said...

Julien ELIE,

Because you asked, it is done. :) One added hyperlinks directly to posts on their ceramic kettles and included a few others that were not previously posted.

One initially included stainless steel and glass kettles but due to the overwhelming size of the post, these will be discussed at length in the next part. They are more modern styles anyways so it fits good with the discussion in the next part.

You are right, iron tetsubins are not always good for everyone especially those at risk of hemochromatosis (iron overload). Considering individual constitutions and internal states when dealing with water have not been touch upon in any of the previous sections of this series as they will be covered extensively in a part in the future that will also look at individual preferences (probably the last Part of this long series).

Thanks for your continued interest.


Matt said...


One and Akira would get along nicely... hahaha...

By the time this series on Harmonizing Water and Tea is over, it may well be the most extensive discussion in English on the subject. And it wasn't with out controversy see here:

Can't wait to see what Akira HoJo says on the subject as his approach is much more scientific and practical.

Have you ever tried dan cong with a Chao Zhou red clay kettle called a sha diao? The kettle is unglazed and sits on a clay stove, fanned with a feather. This is the way the locals prepare water for dan cong in the Chao Zhou style so one can assume that it is the best for dan cong. See here:

One has never tried tea like this before but it looks interesting. On that subject, your series on Chao Zhou teapots was great!

Using a ceramic kettle for dan cong brings out more of its rounder tastes without killing its higher notes. It is probably better for dan cong with a bit of age though.


Nicolas said...

Really great article about water. My english language (poor) stop me to write regulary on your blog. But i can understand with online translator.

I have not seen spécific pages, who gathers yours articles by topic. So the reader must read page per page without topic reference.

Perhaps in the futur, one table of contents can exist. Time is a good friend...

Best regards

David said...

Hi Matt,

It is true Akira has a very pragmatic and scientific approach, but he likes to go to the bottom of things, always looking for the best, to learn, to improve. And he is incredibly generous with his knowledge.

I am sure your series on water will become some kind of reference in the subject. In fact, I think it already is. Too few people are focusing on this. I am not implying that I know better, very far from it. It sounds so logic when you already pay attention to this.

I have read the controversary comments. It doesn't surprise me. On french blogs, we've had more than our share of trolls, arguing and so on.

No, I haven't tried water coming from a Chao Zhou stove. To be honest, as my attention to water is fairly new, I don't think I know enough right now to be able to see a difference. I have to drink more water, analyse things. I have just begun to drink water coming from my pots, kettles, different mineral water. It will take some time for it to pay off. Once I feel more secure about this, I will try water coming from tetsubin, other clay kettles than mine, including Chao Zhou stove, and silver kettle.

Right now, I have quite some work to do ! Fortunately for me, Akira is helping me out, guiding me down this road.

I am looking forward to reading the next issue !

Matt said...


French is also not the strongest language over here, so Google Translator is often employed on this end as well. :) It must be much more difficult for you to comment, so one appreciates your interest and effort.

There was somewhat of an outline of topics in the introduction (Part 1) of this series:

"When selecting the right water for tea these factors should be considered..."

Hope that helps.


One is also guilty of not spending enough attention to water, at least not here on this blog. This series hopes to address some of this oversight by just putting it all out there. One hopes to also learn much from the comments and feed back as well.

Thanks for coming along for the ride.


Ho Go said...

Yes, it's an interesting thread which expands the variables of brewing tea exponentially. Not only will the change in water affect tea, but, the kettle, the teapot, possibly the cup, and, most importantly, the drinker! Of course, the drinker is the most complex of all of these factors. There might be enough motivation to quit one's job and dedicate one's life to this subject. :)

Matt said...


Got to draw the line somewhere. You love that drinker. :)


LTPR said...

Once again my eyes are further opened. Thank you. I'm afraid I have a painfully novice question, if you don't mind. How does one go about heating water in a clay kettle?I honestly have no idea, other than a wood fire (which may just be the answer).

- bev

Petr Novák said...

Matt, your water serial is challenging. And this is good!

can I ask about more info or some links where I can find more about Mr.Akira ?

I have created several clay kettles -some kind of teapots some more like kettles for chanoyu. Impact the clay on water and tea (which we noticed) corresponds with David’s findings -tea was more "rounded", some sharp edges were lost. Problem is with steadiness of the clay on the fire -kettles used only for chanoyu (slowly heated on charcoal oron slow cooking stove) are still in good shape. But some tea friends used them on fast warming "inductive" hot plate and after few mounts it cracked. So ceramic kettles need special care. But I like how water sings when is heating in it.


Matt said...


Glad you enjoy!

You (and Petr below) picked up on where this series is going next- the source of the heat.

You really have to be careful when heating a ceramic kettle/ tang gwan because they can easily break. You should find out what kinds of heat the ceramic kettle can handle before you heat it. Usually the dealer will let you know what kind of heat source should be used. You also must be aware that just because it looks like a ceramic kettle, that doesn't mean that it is meant to undergo high temperatures. This is true for the ceremonial ceramic kettle used in the Korean tea ceremony which looks like it could be used to boil the water, but is actually used just to keep the water warm. If it is a particularly well made ceramic kettle it should be able to handle almost any reasonable heat source as long as there is always a few cups of water in it.

Think you mean hardwood charcoal when you say "wood"? Just plain wood isn't used because it will just smoke up the tearoom. You need a special kind of hardwood charcoal that is smokeless. Of course, you can use other forms of heat as well...

which will be discussed next part (teaser). Hahaha...


This is Akira's Homepage:

Induction heat is problematic for many reasons and should definitely not be used to heat any ceramic kettles. Nothing beats the sound of a kettle lid quivering atop a ceramic kettle, rhythmically keeping beat like at pumping heart while letting plumes of steam out into the air.

Can kettles made of other materials even come close to the ambiance that these create?