Yixing clay that is suitable for yancha

[steanze]

Quick update: I made a back of the envelop calculation for the radiative loss assuming a spherical teapot . The conclusion seems to indicate that this mechanism alone would be sufficient to account for the cooling of a teapot in about one minute, consistent with Kyarazen's measurements.

I will post the details of the calculation later today (by the way, the estimation depends very little on the actual shape of the pot, that is, whether sphere, ellipsoid, or cylinder as the input data are just the total surface area and the volume).

What remains to be understood then why Kyarazen's data (and most people's experience) agrees with a faster cooling rate for flat pots and slower cooling rate for tall pots. I believe that the conductive cooling through the base should account for the difference.

By the way, concerning the differences between the EoT Tian Qi Ni PanHu and the Zini PingGai, I need to point out that the former has much ticker walls, which probably affects also its (thermal) properties, probably much more than the type of clay.

Nice work, thanks!
Did you try comparing the hongni pot to zini or tianqingni? The difference between the effect of tianqingni and zini should be small, between hongni and zini large. Especially if you use green oolong I'd expect a very noticeable difference (and also quite a bit with yancha).

[BW85]

1 flat bottom, flat magic lamp
And... Many pots with the ring.

I haven't personally come across that many flat bottoms

[AT333]

Putting aside the name of clay type (which many agree is just a jargon nowadays) and the shape, every single pot has different performance. If heat loss is one of the main criteria for finding a suitable pot for Yancha, a simple thermometer is good enough to be used for selecting the suitable pot. I would normally go for the end result i.e. testing every pot with other constant factors. What I prefer so far for Yancha are those 50/60s pot, high fired with thinner wall. At times, a thin wall gaiwan is suffice.But I do enjoy reading all these technical discussions and in depth scientific studies, whilst sipping my tea.

[kyarazen]

Putting aside the name of clay type (which many agree is just a jargon nowadays) and the shape, every single pot has different performance. If heat loss is one of the main criteria for finding a suitable pot for Yancha, a simple thermometer is good enough to be used for selecting the suitable pot. I would normally go for the end result i.e. testing every pot with other constant factors. What I prefer so far for Yancha are those 50/60s pot, high fired with thinner wall. At times, a thin wall gaiwan is suffice.But I do enjoy reading all these technical discussions and in depth scientific studies, whilst sipping my tea.

rare stuff sir!....

[xiaobai]

What I prefer so far for Yancha are those 50/60s pot, high fired with thinner wall.

50s/60s yixing? Not good enough! What works best for my yancha is
Qianlong Zhuni!!

Forget about all those modern, 80s, 70s, 60s, or even 50s factory pots. Let's all get some proper Qing dynasty pots and enjoy our yancha in style

Of course, don't forget that water must be boiled in a tetsubin from the Edo era (Taisho or early Showa are not acceptable !) and we must use proper Song dynasty cups

[xiaobai]

Nice work, thanks!
Did you try comparing the hongni pot to zini or tianqingni? The difference between the effect of tianqingni and zini should be small, between hongni and zini large. Especially if you use green oolong I'd expect a very noticeable difference (and also quite a bit with yancha).

You can take a look at some pictures of our side-by-side comparison of the hongni (in fact niangaotu 年糕土) flat shui ping and the tianqingni pan hu here:

https://plus.google.com/u/0/11251849073 ... 6506049969

From the color of the tea soup you may be able to see that the hongni pot performs better and produces a darker/thicker tea soup, which also happens to be mellower. This pot is 90ml and has fairly thin walls.

My impression is that the pan hu cools down too fast (thick walls, small pot = 80 ml) and it is therefore not able to extract enough from the leaves. Thus, the soup is dominated by the roasting notes, which come from the substances (probably sugars, but I am no expert) on the surface of the leaves (the tea is a DHP whose hongbei is on the heavy side). Not much in the soup seems to come from inside the leaves. I think this pot is much better for lightly roasted yancha.

Follow the link for some other pics of the pan hu pot:

https://www.essenceoftea.com/teaware/cl ... panhu.html

The following day, we drunk the same tea from the huanglonghshan zini ping gai. Pics here:

https://www.essenceoftea.com/teaware/cl ... eapot.html

This is a thin-walled pot, a bit larger (95 ml) and not so flat. It has therefore better heat retention. The tea soup was ticker, and mellower, although IMO, a bit less mellow as from the red clay pot but quite good in general.

Finally, we drunk the same DHP from a 100ml 70s F1 hongni shui ping and the result was also quite good, but comparable to the zini ping gai, although I did not do a comparison side by side.

Of course, this is just a comparison for a particular type of yancha. From my experience, I would also agree with you that green oolong is usually better in red clay.

[steanze]

Thanks for the information xiaobai! Yes this is only one data point so it is not enough to prove a general rule, and firing does have important consequences on how clay performs. But it is nice to hear that we have had similar experiences as far as the effect of different clay types are concerned. Sometimes one wonders whether placebo effect is the largest factor

[wert]

What I prefer so far for Yancha are those 50/60s pot, high fired with thinner wall. At times, a thin wall gaiwan is suffice.But I do enjoy reading all these technical discussions and in depth scientific studies, whilst sipping my tea.

I see...would it be possible to share with us what a 50s SP would look like? So that we can all learn from you. Please show the side profile, the base and the airhole.

[steanze]

I think we tend to feel that flat pots cool faster because we compare a flat pot to a tall pot with height equal to the flat pot's length. In which case the surface to volume ratio is different because the flat pot is usually wide as it is long, so it has two relatively large dimensions while the tall pot is both short and narrow.

[AdmiralKelvinator]

Based on the (loose) consensus I've seen here and elsewhere I think a few things can be said at this point. Namely (1) that taller pots tend to retain heat better than short, flat pots and (2) that yancha usually tastes best with very hot, boiling water (excepting perhaps very lightly roasted bai ji guan).

Therefore, If we are aiming for the fullest, most complex taste possible, I think that based on the above a taller pot works best. However, clay type aside, I often see low flat pots recommended for yancha simply because it is easier to put longer leaves inside such a pot. I sometimes wonder if proponents of flatter pots are thinking only about ease of use and not about the actual results.

In my own personal experience, the pot I've come around to using for yancha is indeed a tallish pot with thicker walls.

[kyarazen]

too hot for too long you get the bitterness and roughness in the brew turning it vile, so you need to be just hot enough to get the aromatics come to life, and subsequently delayed over extraction of the excess tea compounds (excess leads to bitter) either by compressing the leaves into a small vessel limiting the swelling, or by a pot that cools fast enough after the initial heat spike. this is why i prefer a flatter pot with a fast pour.

thicker walls help to drop water temp too

Based on the (loose) consensus I've seen here and elsewhere I think a few things can be said at this point. Namely (1) that taller pots tend to retain heat better than short, flat pots and (2) that yancha usually tastes best with very hot, boiling water (excepting perhaps very lightly roasted bai ji guan).

Therefore, If we are aiming for the fullest, most complex taste possible, I think that based on the above a taller pot works best. However, clay type aside, I often see low flat pots recommended for yancha simply because it is easier to put longer leaves inside such a pot. I sometimes wonder if proponents of flatter pots are thinking only about ease of use and not about the actual results.

In my own personal experience, the pot I've come around to using for yancha is indeed a tallish pot with thicker walls.

[xiaobai]

In my own personal experience, the pot I've come around to using for yancha is indeed a tallish pot with thicker walls.

IMO, if you use a tallish pot, you may need to crush part of the leaves and perhaps also use a shorter steeping time.

I have brewed nice yancha in tall (cylinder-like ) pots, but the
best results were obtained by crushing part of the leaves for better
extraction.

Nevertheless, higher heat retention also implies the risk of cooking the leaves and getting too much bitterness (some people do like their tea more bitter than others, so there is plenty of room for personal preferences in this regard).

However, if your pot has relatively thick walls and it is not too large, it may be fairly fine-tuned to get optimal extraction even if you do not crush some of the leaves. Naively, I would expect that thicker walls, being more massive, steal more heat from the pot contents. But perhaps experts and more experienced people can give a more informed opinion on this particular point.

[demonyc]

I've been following this discussion with great interest, there have been lots of really thought-provoking ideas so far! I've also always wondered about the heat retention properties of thick- vs. thin-walled pots since I have heard and read many conflicting theories on this subject.

[hobin]

In my own personal experience, the pot I've come around to using for yancha is indeed a tallish pot with thicker walls.

That makes sense. I've read that the si-ting (tall pear shape) was considered one of the best pots for yancha in the old times. It is tall but has a wider bottom so the leaves find a lot of space...
unfortunately my only si-ting is 130 ml... a tad too big for yancha

[kyarazen]

In my own personal experience, the pot I've come around to using for yancha is indeed a tallish pot with thicker walls.

That makes sense. I've read that the si-ting (tall pear shape) was considered one of the best pots for yancha in the old times. It is tall but has a wider bottom so the leaves find a lot of space...
unfortunately my only si-ting is 130 ml... a tad too big for yancha

that is interesting to hear, because two references, one by weng, and the other by zeng chunan both seem to propose that a flatter pot for both yancha and dancong, but to them the pot should be the size where you can dispense 3-4 cups of tea.

more interestingly, the smaller the pot the easier it cools. if its huge, like a few hundred millilitres then the effects are not prominent within a minute at all