Firing/Density

[Tead Off]

So if the clay body contains grains of SAND........
Back to those sand grains. Sand does not shrink. So around every sand grain is a layer of clay that is shrinking as it dries. The sand grain isn't and something has to give there. So the drying clay forms little microscopic stress cracks around each little sand grain. These too are voids that exist in the clay body.

It gets worse. As the clay begins to fire, it also continues to shrink. So those strain cracks cvontinue to grow and enlarge.

So, the addition of sand into a clay body will automatically create a more porous product after firing, correct? If this is true, then a normally not so porous clay can be made more porous by the addition of sand. In that case, if a tea drinker thought a particular clay to be not so porous, and good for particular kinds of tea, purchases a teapot with this kind of clay, but didn't know the clay had the addition of sand into it, the teapot would react a different way to the tea that the drinker likes to brew in that type of clay pot. This would help to explain why certain teapots made with the same clay don't brew a particular tea the same way. The mixing of clays will alter the nature of how the teapot brews certain teas. And, without knowing either the potter or a representative of the potter, a buyer really can't be sure of what they are getting.

In the case of Yixing, the obsession over which clay is used and the identification of a teapot by a particular clay will not be accurate in many cases because of mixing and other additives. The over-commercialization of Yixing ware has eroded this basic information as to what clay(s) are used. The buyer really enters a guessing game in many cases, if they do not know any real information about the source.

[JBaymore]

Tead off,

Generally... you got it.

Politically incorrect statement coming..............

I hate to say this but.. .... when I was in Yixing last spring....... it QUICKLY became apparent that a lot of what people here discuss as to the orgins and the clays and the firings and and stuff is NOT all that accurate. My admittedly VERY CURSORY experience there (but DEEP experience in ceramics and in Asia) tells me that likely 98 percent of the works that you are seeing in anything other than the really high end places are totally commercially produced and made by semi to fully industrial processes.

Sorry folks... it's the truth as I see it. The level of production in Yixing is VAST..... it is basically a pottery city...... not a quaint village...... and most of the work is NOT what you think. If someone is paying less than about $500 for a Yixing teapot...... it probably is NOT as handmade as it is in the sense that they are thinking it is.

The "good stuff" and the "good clay" and the "good people" and the "traditional process" part of things is generally expensive. I mean EXPENSIVE! I came home with some nice pots ...... but the prices of them would likely give most here a coronary. And they were NOT the "good" ones ...... which are typically in the realm of a minimum of four digits and usually five digits before the decimal point.

Yes... if you are actually IN Yixing and can navigate the back streets and the small workshops... you can find some very decent work that is clearly hand formed by some skilled people (but made from commercial clays and electric or gas fired) in the $100 kind of range.

best,

...................john

PS: The point however is if YOU like the way YOUR pot brews the tea........ it really does not matter.

[tequiero]

Great discussion. Learned a lot from it!
Agree with what John said about yixing. A lot of Chinese don't distinguish real yixing and inferior yixing either. It doesn't help at all that many yixing producers don't have proper academic training in ceramics. Although many renowned yixing artists don't have a bachelor's degree either, for most people, they could use some higher education to help them thoroughly understand the traditional techniques of yixing. Many of them are losing the traditional wisdom of yixing kiln.

[chrl42]

....................john

EDIT: Weird... a posting in between the one above and mine disappeared...... which I was responding to here.

Thank You So Much. All your answers are the best information so far on TC!
Best ~ T

He's very informative, indeed. I can only reply after understanding what he's wrote (so far I'm just reading and borrowing a dict.)


It's pretty attractive situation when Western potters and Eastern potters share the thoughts and discuss...a vast difference in cultures.

In China, a land of 1.5 billion, there seems to be facing 'war of Rare Earth Resources', mostly for aestheric reasons...like Yixing clay, strange stones, wooden spices or even tea leaf. Some rare stones' price has gone up 1000x than it was 20-years ago.

More population means China never has a labor problem, or even technical ones but natural resources are in limited quantity..so it becomes a nightmare.

America continents, on the hand, are in opposite situation...there MUST be great natural super clays and good-looking stones hidden in here and there.

When they've found, can we send Yixing potters over to America and let them make teapots? I don't think it's possible, not in my lifetime though.

The "good stuff" and the "good clay" and the "good people" and the "traditional process" part of things is generally expensive. I mean EXPENSIVE! .

It's not like Yixing teapot was ever cheap, either. During Qing dynasty, Yixing teapot was already comparing with gold. The difference with today is just China became capitalistic, and vast amounts of commericial goods appeared.

Plus, Mao's China founded, and there opened some place called Factory-1. A new ideaology appeared, those masters had to work in factories and teach students. But before that, I don't think Yixing teapot was something purchas-able from the street (correct me if I'm wrong), either.

[Tead Off]

America continents, on the hand, are in opposite situation...there MUST be great natural super clays and good-looking stones hidden in here and there.

When they've found, can we send Yixing potters over to America and let them make teapots? I don't think it's possible, not in my lifetime though.

You only have to look at your own country, Korea, to know that there are excellent clays and excellent potters making teaware. The same for Japan. These places already have a tea culture. Most Japanese tea drinkers don't think about Yixing when they make their sencha/gyokuro. Nor do the Koreans when they reach for their balhyocha or nokcha. I like Yixing teapots and use them regularly, but the obsession with them is commercialized to the point where the good stuff is hard to find and the cheating is beyond anyone's comprehension.

[chrl42]

America continents, on the hand, are in opposite situation...there MUST be great natural super clays and good-looking stones hidden in here and there.

When they've found, can we send Yixing potters over to America and let them make teapots? I don't think it's possible, not in my lifetime though.

You only have to look at your own country, Korea, to know that there are excellent clays and excellent potters making teaware. The same for Japan. These places already have a tea culture. Most Japanese tea drinkers don't think about Yixing when they make their sencha/gyokuro. Nor do the Koreans when they reach for their balhyocha or nokcha. I like Yixing teapots and use them regularly, but the obsession with them is commercialized to the point where the good stuff is hard to find and the cheating is beyond anyone's comprehension.

The Koreans and the Japanese already did explore a thousand years ago, like you said, there are many potters here. There are some places reported to be its clay similar to Yixing clay in mineral compounds, but no additional news, sorry. Japan Kyusu Zhuni is also very similar to Yixing Zhuni, but so far didn't attract my eyes.

Plus, the Japanese tea drinkers did think about Yixing since Meiji period, they called them 唐物 and cherished them many. The reason Japanase don't think about Yixing for another reason is their Chaodo is focused on Matcha ceremony. Nowadays young Japanese abandon tea culture, not only Yixing and follow western culture.

[chrl42]

So if the clay body contains grains of SAND........
Back to those sand grains. Sand does not shrink. So around every sand grain is a layer of clay that is shrinking as it dries. The sand grain isn't and something has to give there. So the drying clay forms little microscopic stress cracks around each little sand grain. These too are voids that exist in the clay body.

It gets worse. As the clay begins to fire, it also continues to shrink. So those strain cracks cvontinue to grow and enlarge.

So, the addition of sand into a clay body will automatically create a more porous product after firing, correct? If this is true, then a normally not so porous clay can be made more porous by the addition of sand. In that case, if a tea drinker thought a particular clay to be not so porous, and good for particular kinds of tea, purchases a teapot with this kind of clay, but didn't know the clay had the addition of sand into it, the teapot would react a different way to the tea that the drinker likes to brew in that type of clay pot. This would help to explain why certain teapots made with the same clay don't brew a particular tea the same way. The mixing of clays will alter the nature of how the teapot brews certain teas. And, without knowing either the potter or a representative of the potter, a buyer really can't be sure of what they are getting.

In the case of Yixing, the obsession over which clay is used and the identification of a teapot by a particular clay will not be accurate in many cases because of mixing and other additives. The over-commercialization of Yixing ware has eroded this basic information as to what clay(s) are used. The buyer really enters a guessing game in many cases, if they do not know any real information about the source.

I believe the relationship between teapot and tea is even MORE complicated than that. Adding a ball clay can enhance the porosity, that's a common belief among Yixing followers, but it can also mean the clay becomes less pure..some people don't like that idea. Many high-quality Yixing clays are pin-pei(mixing), you are right. They say good Pin-pei-ing can supply for what each clay lacks, but old days' there were many clays perfect themselves....and mixing also requires experience, like Puerh pin-pei..nowadays pin-pei changed its meaning to 'poor clay decorating themselves to look good'

It also relates to the mineral compounds (Fe, Si and Al). The minerals and tea have been long discussion, the pots made silica-rich clays tend to give a tea more sweeter note. Iron-rich clays have been worshipped for fragnant teas.

I've read Zhaozhuang Zhuni shrinks less than Xiaomeiyao Zhuni due to high Al amount ZZ Zhuni. It's too complicated subject from mineral to firing...but no, we are talking about clays that are mostly gone from the market.

[wert]

This has been very educational especially from people with experience in pottery. Personally, I feel the tea and the water has more far more effect than the teapot. Does the teapot really absorb the tea particles?Perhaps, it is because I don't have any good teapots.

The prices of yixing is so high mainly due to the chinese market and the relative ignorance of these newcomers. I considered myself quite ignorant in terms of teapots, clay and tea in general. But these newcomers knows as much about yixing as an Eskimo grandma (no offence to eskimo grandmas!) Tea drinking in china is very normal and usual activity but for most part it involve just pouring hot water into tea leaves, nothing remotely interesting, complicated or involved. Gongfu was only practised by southerners (teochews, hokkiens mainly) and popularised by the taiwanese. The rest of china don't really have deep roots in gongfu tea, but because of the culture of "getting 2 dogs if your neighbour has one" Everyone and their dog want a yixing teapot but they can't admit that they know next to nothing about them so it makes them very easy prey for teapot sellers.

[Tead Off]

I am assuming porosity and absorption are used interchangeably by many people. I'm not sure they are exactly the same. But, it seems some pots allow the tea oils to penetrate their walls and accumulate over time. Some would think it was just staining which it is, but a bit more. Now, why would that be an important feature of a teapot?

Many people who love porcelain always talk about aroma and the high notes of a tea's flavor. A somewhat similar effect is achieved with thin walled, higher fired pots which also give you nice aroma and high notes for teas like rolled oolongs.

With teapots that are not particularly thin walled and use more porous clays, I'm really not sure what the advantage is of these pots. People talk about the clay/teapot absorbing and smoothing out some flavors. I understand this and have experienced this and its true. But, why does a tea drinker want to mute a tea's flavor if that tea is really a good tea? For myself, I like to use a porous teapot to take away some storage smells of a poorly stored Puerh, especially a badly wet stored one. But, I'm not sure of the advantage for anything else in using a so called 'porous' teapot.

[chrl42]

I am assuming porosity and absorption are used interchangeably by many people. I'm not sure they are exactly the same. But, it seems some pots allow the tea oils to penetrate their walls and accumulate over time. Some would think it was just staining which it is, but a bit more. Now, why would that be an important feature of a teapot?

Many people who love porcelain always talk about aroma and the high notes of a tea's flavor. A somewhat similar effect is achieved with thin walled, higher fired pots which also give you nice aroma and high notes for teas like rolled oolongs.

With teapots that are not particularly thin walled and use more porous clays, I'm really not sure what the advantage is of these pots. People talk about the clay/teapot absorbing and smoothing out some flavors. I understand this and have experienced this and its true. But, why does a tea drinker want to mute a tea's flavor if that tea is really a good tea? For myself, I like to use a porous teapot to take away some storage smells of a poorly stored Puerh, especially a badly wet stored one. But, I'm not sure of the advantage for anything else in using a so called 'porous' teapot.

Most of antiques (even Zhuni) and Factory-1 are porous. I think your palate is very sensitive or else. Oldies seemed to more focus on the size or shape or water. I'm yet to see old books discussed about porosity of Yixing teapot

Fully sandy (like many recent pots) pots are no fun, they will take the aroma away like you said. But high-quality old clays brew the tea really find and make its soup more vibrant...it depends on the palates and the clays IMHO.

Ye Han-zhong wrote (the only successor of Chaozhou Gongfu Cha) 潮州工夫茶话 (ass-kicking book), in that he mentioned "Yixing teapot plays a main role of Gongfu ceremony, without Yixing Zhuni, then it's not Gongfu.
Gaiwan plays worse because Gaiwan is fully open, so the aroma will easily go away"

[Tead Off]

I am assuming porosity and absorption are used interchangeably by many people. I'm not sure they are exactly the same. But, it seems some pots allow the tea oils to penetrate their walls and accumulate over time. Some would think it was just staining which it is, but a bit more. Now, why would that be an important feature of a teapot?

Many people who love porcelain always talk about aroma and the high notes of a tea's flavor. A somewhat similar effect is achieved with thin walled, higher fired pots which also give you nice aroma and high notes for teas like rolled oolongs.

With teapots that are not particularly thin walled and use more porous clays, I'm really not sure what the advantage is of these pots. People talk about the clay/teapot absorbing and smoothing out some flavors. I understand this and have experienced this and its true. But, why does a tea drinker want to mute a tea's flavor if that tea is really a good tea? For myself, I like to use a porous teapot to take away some storage smells of a poorly stored Puerh, especially a badly wet stored one. But, I'm not sure of the advantage for anything else in using a so called 'porous' teapot.

Most of antiques (even Zhuni) and Factory-1 are porous. I think your palate is very sensitive or else. Oldies seemed to more focus on the size or shape or water. I'm yet to see old books discussed about porosity of Yixing teapot

Fully sandy (like many recent pots) pots are no fun, they will take the aroma away like you said. But high-quality old clays brew the tea really find and make its soup more vibrant...it depends on the palates and the clays IMHO.

Ye Han-zhong wrote (the only successor of Chaozhou Gongfu Cha) 潮州工夫茶话 (ass-kicking book), in that he mentioned "Yixing teapot plays a main role of Gongfu ceremony, without Yixing Zhuni, then it's not Gongfu.
Gaiwan plays worse because Gaiwan is fully open, so the aroma will easily go away"

No argument from me about old clay being better. With gongfu cha, both gaiwan and thin walled teapot work well. Aroma does not go away unless one leaves the lid off. Aroma is primary with gaiwan. One of the joys of using gaiwan is smelling the lid!

These kinds of statements about gaiwan being worse are very misleading. Not every zhuni teapot is going to brew world class tea. Too many variables. I thought this thread was showing how difficult it is in making conclusions about clay and its firing. You are on a one track road, Charlie.

[chrl42]

Hehe, right. He added that ever since Chaozhou ren switched from Wuyi to Dancong, Gaiwan replaced Yixing & Shantou's status.

I always thought Ye Han-zhong as one who likes public's spotlight and TV, yet he's very few left who can discuss about Gongfucha all night long. I also don't believe clayware can deliever the aroma better than porcelain. I just thought porous pots are easier to treat and liked the way they manipulate the tea taste. It's late...gotta go grub, peace.

[JBaymore]

Nowadays young Japanese abandon tea culture, not only Yixing and follow western culture.

Yup......... I spend a lot of time in Japan and see this. Coffee has replaced tea, and beer has replaced sake.

There ARE some young people re-interpreting Chado in a far more contemporary fashion..... but it is "few and far between".

best,

..................john

[wert]

There is another thing I am curious about. How does the rate that water dries off the clay relates to the firing? Does that ties in directly with the porosity of the clay?

It might be obvious but I am...curious as I notice that zisha dries at different rates.

[tst]

I think too many factors can affect the rate of evaporation ... air temperature, clay temperature, amount of air flow on the clay, etc ... in addition to the clay type and firing.

All other things equal except the firing, I'll leave it to someone else to weigh in.