Help with long dan shaped teapot

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LeoFox
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Sun Sep 13, 2020 5:46 pm

I recently purchased an 85 mL long dan shaped porcelain teapot, resembling this one:

Image

This was motivated by an old post from teamaster:
http://teamasters.blogspot.com/2012/04/ ... t.html?m=1

Furthermore, I was told this type of pot allows ball rolled oolongs to fully expand upwards, allowing for improved brewing.

However, i was also warned not to use more than about 3 grams of ball rolled oolong in my pot. Usually, i brew at 6-6.5 g /100 mL, which would translate to around 5.1-5.5 g/ 85 mL, so i was taken aback.

Nonetheless, i tried to brew 3 g of high mountain oolong in the pot for 1 min / 50 sec / 1:30 for first 3 steeps. These are around double the time i normally use in my 125 mL pot with 8 grams of the same tea. However, the tea was very bland and weak in the long dan.

Next, i tried brewing 5.3 g in the long dan pot using my usual 30 sec / 25 sec / 45 sec steep times. Surprisingly, the brew was almost equally bland as when i used 3 grams, but now it had more astringency. The astringency worsened with more steeps. When i cleaned out the pot, i noticed some heavily concentrated (and very bitter) liquid was being trapped in the bottom under the dense layers of leaves, that was probably contributing to the problem. This was not evident when i was only using 3 grams of tea.

I was wondering if anyone else here has experience using a small long dan pot and can provide some advice to me regarding proper use with ball rolled oolong. Thank you!
Last edited by pedant on Mon Sep 14, 2020 2:45 pm, edited 1 time in total.
Reason: mod edit: fixed hotlinking issue
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Bok
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Sun Sep 13, 2020 7:31 pm

Many factors could be at play... maybe the pot is just too thick walled, overstepping your leaves. Your tea might simply be not of good enough quality and the porcelain emphasises it’s short comings.

I think this kind of statements, x y shape is for this tea and that to be mostly rubbish. With a little adapting almost any shape can be used for any tea.

In this case the slightly taller round-ish shape will not perform different than a perfectly round or lower round shape. That is just uninformed bs.
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LeoFox
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Sun Sep 13, 2020 10:27 pm

Bok wrote:
Sun Sep 13, 2020 7:31 pm
Many factors could be at play... maybe the pot is just too thick walled, overstepping your leaves. Your tea might simply be not of good enough quality and the porcelain emphasises it’s short comings.

I think this kind of statements, x y shape is for this tea and that to be mostly rubbish. With a little adapting almost any shape can be used for any tea.

In this case the slightly taller round-ish shape will not perform different than a perfectly round or lower round shape. That is just uninformed bs.
In this case, the longdan pot is very thin walled compared to my usual pot, which is flatter, thicker and holds 125 mL and is also porcelain. I will try again with a higher quality tea.
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Bok
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Sun Sep 13, 2020 10:38 pm

@LeoFox best if you do a side by side comparison with the two pots to see the difference more clearly.
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LeoFox
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Sun Sep 13, 2020 10:45 pm

Bok wrote:
Sun Sep 13, 2020 10:38 pm
LeoFox best if you do a side by side comparison with the two pots to see the difference more clearly.
You are right. In between using my usual pot and the longdan pot, i had a medium fired dong ding. That may have killed my palate, though there was an interval of several hours in between. I will try again. Thank you for your advice
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LeoFox
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Mon Sep 14, 2020 1:54 pm

Bok wrote:
Sun Sep 13, 2020 7:31 pm
Many factors could be at play... maybe the pot is just too thick walled, overstepping your leaves. Your tea might simply be not of good enough quality and the porcelain emphasises it’s short comings.

I think this kind of statements, x y shape is for this tea and that to be mostly rubbish. With a little adapting almost any shape can be used for any tea.

In this case the slightly taller round-ish shape will not perform different than a perfectly round or lower round shape. That is just uninformed bs.
Taking your cue that temperature might be the issue, i performed a side by side time course with boiling water. I heated both pots with boiling water for 15 seconds and refilled with boiling water, measuring the temperature every 30 seconds.

Won't regurgitate all the numbers here but briefly, (long dan, flat) ( temps taken at ~center point)
starting temp: (97C, 97C)
1 min: (89C, 91C)
2 min (88C, 86C)
5 min (81C, 78C)
10 min (70C, 65C)
Within the first 3 min, the temperatures are very similar. Afterwards, the center of the longdan pot becomes consistently 3-5 C hotter than the flatter pot i use. The flatter pot which looks like this one:

Image

Has consistently lower temperature across different points of the interior. This is surprising since the long dan is much thinner (i can see outline of my finger through walls) compared to the flatter pot. If the long dan had thicker walls, the temperature retention, i expect would be amazingly good, esp at the center. I want to note that away from the center, the temperature in the long dan is almost the same as the flat pot.

This suggests to me that one issue with the long dan pot is uneven heating, and the potential for overcooking at the hot focal center. It makes me wonder if the pot might be more suitable for unrolled tea that are less expansive.

I have yet done the side by side tasting but this will come. I tried one more time with the long dan alone using 5.2 g high mointain balls, and the result was pathetic.
Last edited by pedant on Mon Sep 14, 2020 2:45 pm, edited 1 time in total.
Reason: mod edit: fixed hotlinking issue
faj
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Mon Sep 14, 2020 2:09 pm

LeoFox wrote:
Mon Sep 14, 2020 1:54 pm
This is surprising since the long dan is much thinner (i can see outline of my finger through walls) compared to the flatter pot. If the long dan had thicker walls, the temperature retention, i expect would be amazingly good, esp at the center.
You expect heat retention to be better in a thicker pot. There are a couple of things to temper this expectation.
  • You think you have preheated both pots equally. A thicker pot will probably absorb more heat before it reaches a "fully preheated" condition, so likely your thicker pot was not heated as evenly as your smaller one. It might have had more "room" left to absorb heat from your tea, if you will.
  • You assume both pots have the same thermal properties. But if your thinner pot is made of a clay that has better insulation properties, this might easily more than compensate for thickness. I do not know, however, if insulation properties varies much between clays.
There is one other factor you are not taking into account, and it might be a big one : surface area of the exposed water. Your tea probably cools from losing heat at the air/water interface faster (by unit of surface) than it loses heat through the walls. I would assume your flat pot to have a much larger area of exposed water at the top. I cannot say overall what portion of heat losses come from each cooling mechanism, but this might, too, be a contributing factor.
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LeoFox
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Mon Sep 14, 2020 2:40 pm

faj wrote:
Mon Sep 14, 2020 2:09 pm
LeoFox wrote:
Mon Sep 14, 2020 1:54 pm
This is surprising since the long dan is much thinner (i can see outline of my finger through walls) compared to the flatter pot. If the long dan had thicker walls, the temperature retention, i expect would be amazingly good, esp at the center.
You expect heat retention to be better in a thicker pot. There are a couple of things to temper this expectation.
  • You think you have preheated both pots equally. A thicker pot will probably absorb more heat before it reaches a "fully preheated" condition, so likely your thicker pot was not heated as evenly as your smaller one. It might have had more "room" left to absorb heat from your tea, if you will.
  • You assume both pots have the same thermal properties. But if your thinner pot is made of a clay that has better insulation properties, this might easily more than compensate for thickness. I do not know, however, if insulation properties varies much between clays.
There is one other factor you are not taking into account, and it might be a big one : surface area of the exposed water. Your tea probably cools from losing heat at the air/water interface faster (by unit of surface) than it loses heat through the walls. I would assume your flat pot to have a much larger area of exposed water at the top. I cannot say overall what portion of heat losses come from each cooling mechanism, but this might, too, be a contributing factor.
Thank you for your input. I agree with all your points.

I am interested mainly in the quality of the tea i produce in the way i usually make tea. I tend to heat pots for 15 seconds before use and so that is why did the experiment in this way. Both pots are porcelain and bought from the same taiwanese vendor with the same symbol at the bottom.

Ultimately, i feel that the temperature differences are minor (3 - 5 degrees) and may not explain the big difference in taste quality. I will do a side by side test soon with ball rolled oolong and some yan cha for comparison. If the longdan fails for both teas, then it would really seem to me that it's not very functional.
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Tor
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Tue Sep 15, 2020 3:12 am

What kind of filter does the new teapot have? You mentioned that there’s some water trapped inside and that could be from the filter design.
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Tor
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Tue Sep 15, 2020 3:23 am

Regarding the tea comes out bland, I’ve found that some porcelains have this kind of character. I guess it’s from the type of glaze used. I have too many nice cups, both antique and modern, that have this ‘character.’

Try brewing tea from another teapot or gaiwan and use the Long Dan as a fair cup. See how it goes.
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LeoFox
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Tue Sep 15, 2020 6:01 am

Tor wrote:
Tue Sep 15, 2020 3:12 am
What kind of filter does the new teapot have? You mentioned that there’s some water trapped inside and that could be from the filter design.
Both have 4 holes in the porcelain.

In terms of the glaze, they look very similar to each other but that is a good point. I have experienced muting as well from certain glazed cups. I have a very nice looking kyoto yaki yunomi that is unusable for this reason
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Bok
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Tue Sep 15, 2020 7:14 am

LeoFox wrote:
Tue Sep 15, 2020 6:01 am
Tor wrote:
Tue Sep 15, 2020 3:12 am
What kind of filter does the new teapot have? You mentioned that there’s some water trapped inside and that could be from the filter design.
Both have 4 holes in the porcelain.

In terms of the glaze, they look very similar to each other but that is a good point. I have experienced muting as well from certain glazed cups. I have a very nice looking kyoto yaki yunomi that is unusable for this reason
I’m always very cautious with Japanese glazed teaware, I’ve had this issue a couple of times.

Flat shapes will indeed dissipate heat faster due to the reason faj mentioned. So everything else being equal the egg will cook your leaves more.

In this kind of situation I’d adapt to the following: faster steeps.

Always leave lid off in between, when pot is empty of water.

If the tea still has issues, change to a similar tea and other teas and see how those fare side by side in the two pots.
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LeoFox
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Tue Sep 15, 2020 11:29 am

Bok wrote:
Tue Sep 15, 2020 7:14 am
LeoFox wrote:
Tue Sep 15, 2020 6:01 am
Tor wrote:
Tue Sep 15, 2020 3:12 am
What kind of filter does the new teapot have? You mentioned that there’s some water trapped inside and that could be from the filter design.
Both have 4 holes in the porcelain.

In terms of the glaze, they look very similar to each other but that is a good point. I have experienced muting as well from certain glazed cups. I have a very nice looking kyoto yaki yunomi that is unusable for this reason
I’m always very cautious with Japanese glazed teaware, I’ve had this issue a couple of times.

Flat shapes will indeed dissipate heat faster due to the reason faj mentioned. So everything else being equal the egg will cook your leaves more.

In this kind of situation I’d adapt to the following: faster steeps.

Always leave lid off in between, when pot is empty of water.

If the tea still has issues, change to a similar tea and other teas and see how those fare side by side in the two pots.
I just did a side by side using an old packet of da hong bao i had lying around:

Image

Same ratios, brew parameters, type of cups, etc.

The result was interesting:

The long dan had a much more concentrated and rich flavor for all steepings. In particular, the more dried fruit notes were really explosive in the first 3 steepings and the second steeping even had a sharp peppery note.

In contrast, the flatter pot was much more subdued, though i got more nuances of different chocolate notes than the long dan. The dried fruit was there but not very pronounced compared to the chocolate and coffee notes. There was no pepperiness. It almost seemed like 2 different teas.

In this case, the long dan seemed to perform better, possibly due to the more concentrated temperature that it can achieve.

I'm starting to wonder if long dan is simply better for unrolled teas that can take more temperature. Later this week i will do a side by side with keemun black and then a dan cong. I have seen many CZ long dan.
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Bok
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Tue Sep 15, 2020 7:50 pm

I doubt it’s only the shape... and for what it’s worth most Yancha fares best in flatter shapes due to the leaf shape.

You can only jump to conclusions like this if you compare various Dragonegg shaped pots in different clays. Other than that it’s just this particular pot behaving that way.
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LeoFox
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Tue Sep 15, 2020 9:15 pm

Bok wrote:
Tue Sep 15, 2020 7:50 pm
I doubt it’s only the shape... and for what it’s worth most Yancha fares best in flatter shapes due to the leaf shape.

You can only jump to conclusions like this if you compare various Dragonegg shaped pots in different clays. Other than that it’s just this particular pot behaving that way.
You are right. This is just n=1. Of course, was hoping someone with experience using long dan in other clays can jump in about this. I am simply using porcelain, and so i am hoping there is no clay/glaze adsorption or leaching impact to confuse things. The primary factors should just be geometry and heat.

From a historic point of view, these long dan type pots have existed way before the development of tightly rolled oolong...
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