Yixing lid test?

[Tead Off]

Lid fit IS an important element for many long time tea drinkers. I find that even with great clay, a poor fitting lid can be so annoying that the thought of getting rid of the pot creeps into my tea experience often. Of course, this is very subjective, but I believe very common with tea drinkers. This has nothing to do with the quality of the tea that it brews but can affect value when it comes to selling off older and more collectible teapots.

[MarshalN]

I was talking about a good product with good lid fit and well made air hole. When air leaks from everywhere, there isn't as strong, focused air force to push a perfect pouring.

Actually, air doesn't leak, air comes in from all sides and water exits from the spout.

You might want to try it out with a can of evaporated milk.

And again, you have to qualify it by saying "well made air hole." My whole point is lid fit IN AND OF ITSELF is not a useful indicator of anything functionally related. In fact, in the wrong circumstances (such as too-small air hole) it's actually a problem.

Lid fit IS an important element for many long time tea drinkers. I find that even with great clay, a poor fitting lid can be so annoying that the thought of getting rid of the pot creeps into my tea experience often. Of course, this is very subjective, but I believe very common with tea drinkers. This has nothing to do with the quality of the tea that it brews but can affect value when it comes to selling off older and more collectible teapots.

Of course, but I think the thread was talking about buying pots for use, not for collectors, who go by a different set of criteria (maker, style, provenance, size, etc etc). Also, a lid that fits well enough can still not pass the so called lid fit test but have no problems during normal usage.

Just a reminder of the lid fit test that is being referenced in this thread:

One simple way to test is to fill the teapot with 2/3 full of water and invert the teapot, with your finger tightly sealing the opening of the spout. The teapot cover should not fall off, showing that it is tightly sealed.

[Tead Off]

point taken, and I don't think the lid fit test should be a criteria of passing on a good pot with good clay which doesn't have a perfect lid fit as evidence of all the good factory 1 pots with less than stellar workmanship.

[chrl42]

Lid fit IS an important element for many long time tea drinkers. I find that even with great clay, a poor fitting lid can be so annoying that the thought of getting rid of the pot creeps into my tea experience often. Of course, this is very subjective, but I believe very common with tea drinkers. This has nothing to do with the quality of the tea that it brews but can affect value when it comes to selling off older and more collectible teapots.

I've seen some antiques with a discount for bad pouring, but not lid-fit (not yet)..antique Yixings I've seen or used have a quite ok lid-fit than they look..even those 5~80cc Chaozhou Gongfu Zhuni pots. Maybe because old time they fired in the Dragon kiln in lower temp for days..I dunno.

Lid-fit problem more pops up with mass-produced Factory-1 pots (48-hr firing)..some users or sellers 'ground' the lips of the body and the lid for better attaching. But I didn't see reputable vendors do that.

Modern day potters solve the lid-fit problem by 2-time firing. First they fire a pot, then grind the lips of lid/body, then fire again. But many famous potters still maintain 1-time traditional firing. Maybe they might think it's more natural for pots, or they wanna demonstrate their 'skills' for pots to have a good lid-fit even with a 1-time firing...correct me if I'm wrong

[William]

No doubt lid play lesser role in making a good cup of tea, usually good pot, good clay, good workmanship , good lid fitting , good shape , and everything else come together.

Hardly one will get good pot , but lousy fitting lid, or bad shape.

Under a master craft, everything else come together.
Only question is how to make a good cup of tea using that pot.

I have seen a couple of Ming ~ ROC period teapots made with really good clay, most of them were with a bad lid fitting, so I would not be too sure that good clay and good lid fitting come together.

[JBaymore]

When air leaks from everywhere, there isn't as strong, focused air force to push a perfect pouring.

Air moving into a teapot does not "push" anything.

The mass of the water (oops... "tea"'), having found a way out of the enclosed space due to the effects of gravity on that mass (when the pot is tipped so that the spout inlet is below the level of the surface of the liquid), leaving the interior volume of the pot then increases the size of the "empty space" inside the pot.

This original "empty space" is actually not empty..... it is filled with air molecules that are at a packing density approximating the effects of 14 pounds per square inch of atmospheric air pressure upon those molecules.

When the liquid leaves the enclosed space, for an instant, it is causing the air molecules inside the teapot to spread out to fill the now larger volume of so-called "empty" space. As the packing density of the air molecules decreases, so does the atmospheric pressure inside the space.

Differential in pressure provides potential Force to induce gas flow.

SO...... "nature abhors a vacume" .... and almost instantaneously air from outside the pot will then flow in to replace the volume of the liquid that is leaving) if there are any openings in the pot to the outside. This air moving into the teapot is not pushing on anything... it is being PULLED into the space due to the differential in pressure between the outside and the inside created by the exiting tea. The tea LEAVING iof "pulling" the air in. That inward flow is just trying to keep the pressure inside from being LOWER than where it started out.

There is no more (higher) pressure inside the pot when it is being poured than when it is sitting on the table....which would be necessary for the word "push" to apply in any way. At the most the pressure inside the pot is almost impreceptibally LOWER than the outside atmospheric pressure while the tea is being poured. The lower it gets the more it actually inhibits the pouring of the tea.

If air cannot get into the interior of the pot, eventually the pressure of the surrounding air on the OUTSIDE of the pot, pressing on the surface of the mass of liquid trying to come out of the spout, will reach a point where it is opposing the impact of the force of gravity on the mass of liquid (pressure inward is equal to the pressure directed outweard) and the tea no longer will come out of the spout.

As to if it is important for air to ONLY come in thru the vent hole on the lid or not..........

I sincerely doubt that the air flow characteristics (such as laminar versus turbulent flow) in the TINY interior space of the pot will have much if anything to do with the flow of tea out the spout.

It is only necessary that the total volume of the air inlet be sufficient (relative to the size of the spout opening at "full pour") that the negative pressure created by the vacating tea not become so great as to negatively impact the flow of the tea.

That's the opinion of a professional potter and a bit of a "tech weenie" on the sciences side of things.

best,

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

[theredbaron]

I have several pots with bad lid fit, and/or too small air holes. But it is often a question of getting to know your pot.
In terms of bad lid fit, one of my factory 1 shui ping has such a bad lid fit that it tends to pour through the gap between pot and lid. But it also has one good spot where lid and pot are well aligned, where it pours perfectly. It's then just a question of hitting that spot.
Small airholes can be compensated by slightly lifting the lid with your index finger while pouring, enabling more airflow through the widened gap between pot and lid.

Of course a pot with good clay, and perfect craftsmanship is always preferable, but often not attainable - especially when we talk about older pots. When it comes to the necessary compromises, i would rather compromise on issues such as lid fit than clay quality.

This is an old argument between people who are primarily tea pot collectors, where craftsmanship is the deciding factor in the selection of pots, including artists' pots which are often not even really suitable for use, and people who are primarily tea drinkers, who look for pots that are most suitable to enhance the taste of the tea, and where perfect craftsmanship is secondary.
Tea drinkers, for example, love factory 1 shui ping, due to the clay, while collectors mostly ignore them as more often than not craftsmanship is quite poor, and pots cannot be attributed to famous artists.

[chrl42]

I have several pots with bad lid fit, and/or too small air holes. But it is often a question of getting to know your pot.
In terms of bad lid fit, one of my factory 1 shui ping has such a bad lid fit that it tends to pour through the gap between pot and lid. But it also has one good spot where lid and pot are well aligned, where it pours perfectly. It's then just a question of hitting that spot.
Small airholes can be compensated by slightly lifting the lid with your index finger while pouring, enabling more airflow through the widened gap between pot and lid.

Of course a pot with good clay, and perfect craftsmanship is always preferable, but often not attainable - especially when we talk about older pots. When it comes to the necessary compromises, i would rather compromise on issues such as lid fit than clay quality.

This is an old argument between people who are primarily tea pot collectors, where craftsmanship is the deciding factor in the selection of pots, including artists' pots which are often not even really suitable for use, and people who are primarily tea drinkers, who look for pots that are most suitable to enhance the taste of the tea, and where perfect craftsmanship is secondary.
Tea drinkers, for example, love factory 1 shui ping, due to the clay, while collectors mostly ignore them as more often than not craftsmanship is quite poor, and pots cannot be attributed to famous artists.

Truth is artists' pots ARE very suitable (even antiques) for use and are made of better clay than any other else. That's the characteric of Yixing teapot. What those potters do in Yixing is to communicate with customers and make pots, many are heavy tea drinkers, too. Functionality can never part from Yixing, ask experienced collectors to name Yixing masterpiece..they would say Shi-piao, Li-xing..the simplest shapes which at a time are the hardest shape to make. The highest price at auction was Gu Jing-zhou's Shi-piao if remembered correctly.

The fact is lid-fit thingy (test) and others popped out quite recently, many are from those commercial books...I've never read those theories from books written authorities..(this test should be only applied on modern 2-time firing commercial pots to be exact) tell that lid-fit test to one of grand masters...I wonder their opinions I mean, why not apply that test on Kyusu or some Korean teawares, but only Yixings?

As for Factory-1 pots, there might be some lid-fit errors, but rarely have air-hole or pouring problems...they were the products of a huge organization..there is something called 'product management'.

[Hmm]

Can't we assume to a certain degree that if we are not buying an antique pot, then a prerequisite for a pot with good clay is also that it has decent craftsmanship?

Knowing that the price of good clay is increasingly expensive, who is going to craft a poorly made pot with good clay these days?

[theredbaron]

Truth is artists' pots ARE very suitable (even antiques) for use and are made of better clay than any other else. That's the characteric of Yixing teapot. What those potters do in Yixing is to communicate with customers and make pots, many are heavy tea drinkers, too.

What about those rather largish pots with very complex shapes and massive decorations for the collectors market, depending on artist, costing thousands of dollars, or more?

Of course, if we talk about antique master pots... but how many people actually could afford such a pot, and then even risk drinking from them?

[gingkoseto]

I was talking about a good product with good lid fit and well made air hole. When air leaks from everywhere, there isn't as strong, focused air force to push a perfect pouring.

Actually, air doesn't leak, air comes in from all sides and water exits from the spout.

You might want to try it out with a can of evaporated milk.

And again, you have to qualify it by saying "well made air hole." My whole point is lid fit IN AND OF ITSELF is not a useful indicator of anything functionally related. In fact, in the wrong circumstances (such as too-small air hole) it's actually a problem.

Well the air pressure thing is very straight forward in my eyes, and it's only one of the major aspects why lid fit is functionally important. I didn't invent any of these theories either. It's widely documented that lid fit is an important functional criterion of yixing, and I know people who examined on hundreds of teapots about their lid fit and function. So far I have yet to see one yixing book or article authored by yixing experts claiming lid fit is not important (much to the contrary, many of them mentioned it as a functional test) and I have yet to met one yixing craftsman who would claim he doesn't think lid fit is one of the very important standards he would hold for his teapots. But you don't have to agree with me or them.

I have no intention to make other people agree with me. I got involved in this discussion because I was really shocked to see some people (even more than one or two... and all in one place...) said "lid fit test is useless and has nothing to do with function" as if it were an absolute truth. Being shocked is not a sign of blaming on people holding that opinion, but rather because I didn't see many people saying this before. So I thought I should emphasize the other side of the opinion. And of course next time I shall not be shocked.

[gingkoseto]

those theories from books written authorities..
...I wonder their opinions

That Han Qilou book you recommended, chapter 9.
A Xu Xiutang book mentioned it too, and I think I've seen more.

I mean, why not apply that test on Kyusu or some Korean teawares, but only Yixings?

It doesn't seem to work that well on most other ceramic or porcelain textures, due to either too smooth or too coarse surfaces. In this aspect yixing clay is quite unique.

[chrl42]

Well the air pressure thing is very straight forward in my eyes, and it's only one of the major aspects why lid fit is functionally important. I didn't invent any of these theories either. It's widely documented that lid fit is an important functional criterion of yixing, and I know people who examined on hundreds of teapots about their lid fit and function. So far I have yet to see one yixing book or article authored by yixing experts claiming lid fit is not important (much to the contrary, many of them mentioned it as a functional test) and I have yet to met one yixing craftsman who would claim he doesn't think lid fit is one of the very important standards he would hold for his teapots. But you don't have to agree with me or them.

It's only important when you select 'commercial' pots..but serious collectors will more care about clay or firing or overall balance even if they are to select commercial pots. Point here is lid-fit IS important, but there are things much more important than lid-fit in Yixings.

Lid-fit problem can be solved by 2-time firing or grinding the lips of lid-body anytime..but why do you think famous masters still maintain 1-time firing (in this way even master pots could cause 'lid-fit' problem) or reputable vendors or collectors refuse to grind them?

Lid-fit theory mentioned in books are also in *guideline*, guideline is usually for beginners, you read Han Qi-lou book for the depth of firing and study of kilns and overall history, NOT guideline written in hidden chepters..the very guidelines can be found in 10-rmb Yixing books very often, because their target is mainly beginner. Ah..this discussion is going nowhere..

I mean, why not apply that test on Kyusu or some Korean teawares, but only Yixings?

It doesn't seem to work that well on most other ceramic or porcelain textures, due to either too smooth or too coarse surfaces. In this aspect yixing clay is quite unique.

So, can you tell that Yixing is superior to others cos those 100-rmb Yixings pass the test and Kyusus don't?

[ethan]

The advice of an amateur:

If one is buying a pot for his own use, he should test it. If he must keep a finger on the lid or bear w/ a little drip etc., would he enjoy using the pot (day in, day out, over the years)?

If one is buying a pot to look at, then all that is necessary is that he enjoys looking at it; and, he won't mind giving the pot away when it fails to please him so in the future (not leaving it for heirs to dispose of).

If one is buying a pot as an antique treasure and/or investment, it must work very well & not draw eyes to imperfections. Such a pot is most likely to be sold when he is desperate for $ or dead. When broke, it is awful to deal w/ potential buyers balking at a purchase at a fair price over "minor flaws". Nor should one's survivors face hearing that his "treasures" are flawed & not "heirlooms" of such great value. (It does not matter whether that is true. Flaws draw "devaluing" words.)

Thanks for the discussion here. Surprised that the explanations of how pouring works, did not include the phrase "partial vacuum".

[gingkoseto]

So, can you tell that Yixing is superior to others cos those 100-rmb Yixings pass the test ...

Again this deviates from my original points of discussion and goes back to the loop 3 pages ago. I feel at this point, (most of) everybody has got everybody else's point, or too exhausted to comprehend it.