Effect of unglazed Japanese teapots on taste?

[t4texas]

There have been many discussions on the effect of Yixing clays on the taste of teas brewed in them, but what about the effect of various Japanese clays on the taste of Japanese green teas? Can you tell a difference vs porcelain? Does it improve over time?

[Salsero]

I don't think I have ever made sencha in porcelain. Do you think it's possible? I just started out with kyuusu or other unglazed clay pots and have never thought twice about it.

Of course with Chinese (except greens), I have done gaiwan as well as yixing pot, but I have not been so adventurous with Japanese greens.

[Chip]

I have brewed in porcelain and glazed pots, no problem.

I have obviousy also brewed in unglazed clay many times. My first kyusu was an entry level terre cotta colored unglazed kyusu. I used it virtually everyday for 5-6 years. One day after I bought another kyusu, I suddenly realized that the sencha was always sweeter in the old kyusu. Unfortunatley, that kyusu is long gone after suffering many chips and breaks til I finally had to give up on it.

Still, this is not like Yixing which I think seasons much quicker. Tokoname clay seems much denser to me and less apt to season like a Yixing.

[t4texas]

Salsero - "Except greens" meaning no to Chinese greens in a Yixing? If Japanese unglazed clay works with Japanese greens why would not Chinese greens work in a Yixing? I know most people believe that, but why? The usual caveat has to do with accidentally over-brewing greens and tainting the Yixing clay with bitterness. But why wouldn't this be a danger with Japanese greens in an unglazed Japanese pot?

I do have one thin-walled Yixing I brew Chinese greens in and it works well.

[Tead Off]

Salsero - "Except greens" meaning no to Chinese greens in a Yixing? If Japanese unglazed clay works with Japanese greens why would not Chinese greens work in a Yixing? I know most people believe that, but why? The usual caveat has to do with accidentally over-brewing greens and yainting the Yixing clay with bitterness. But why wouldn't this be a danger with Japanese greens in anun unglazed Japanese pot?

I do have one thin-walled Yixing I brew Chinese greens in and it works well.

True, true.

I notice a definite difference brewing green tea in a purple banko and also with good Bizen clay teapot. The Bizen has surprised me enormously, even with Yohen.

[t4texas]

I have brewed in porcelain and glazed pots, no problem.

I have obviousy also brewed in unglazed clay many times. My first kyusu was an entry level terre cotta colored unglazed kyusu. I used it virtually everyday for 5-6 years. One day after I bought another kyusu, I suddenly realized that the sencha was always sweeter in the old kyusu. Unfortunatley, that kyusu is long gone after suffering many chips and breaks til I finally had to give up on it.

Still, this is not like Yixing which I think seasons much quicker. Tokoname clay seems much denser to me and less apt to season like a Yixing.

Thanks for the perspective. I am guessing that its best not do an initial seasoning like you would for a Yixing since there would be some danger of imparting bitterness to the clay. So more of a longer-term seasoning-by-use.

But is there any way to push that along? Does anyone let green leaves float in water in the pot after they have been brewed. I do that routinely with Yixings for Oolongs, reds, and pu-erhs.

[Tead Off]

I have brewed in porcelain and glazed pots, no problem.

I have obviousy also brewed in unglazed clay many times. My first kyusu was an entry level terre cotta colored unglazed kyusu. I used it virtually everyday for 5-6 years. One day after I bought another kyusu, I suddenly realized that the sencha was always sweeter in the old kyusu. Unfortunatley, that kyusu is long gone after suffering many chips and breaks til I finally had to give up on it.

Still, this is not like Yixing which I think seasons much quicker. Tokoname clay seems much denser to me and less apt to season like a Yixing.

Thanks for the perspective. I am guessing that its best not do an initial seasoning like you would for a Yixing since there would be some danger of imparting bitterness to the clay. So more of a longer-term seasoning-by-use.

But is there any way to push that along? Does anyone let green leaves float in water in the pot after they have been brewed. I do that routinely with Yixings for Oolongs, reds, and pu-erhs.

I think seasoning is a myth. When you start with good clay, how can you brew a bad pot of tea? Frequent use of a good teapot is all you need. Drying your teapot after a session with hot water and a good rub will keep the beauty of the pot intact. Personally, I don't want stains on my pots.

I think it's important to sanitize both a new and old pot. No need to boil yixing for hours or any other of these crazy fetishistic rituals. Oldwives tales. Good tea in, good tea out. Start with good clay and you can't go wrong. When I run these kinds of things past my old tea advisors, they look at me like I'm nuts.

[Chip]

I do not know about Yixing, but Tokoname just needs some good rinsing with hot water before first use. Hagi on the other hand could require some initial soaking, and it is recommended.

Yixing is such a different animal altogether. I do not brew Chinese greens in Yixing anymore, prefering either glass method or porcelain. My personal experience was that Yixing seemed to mute Chinese greens somewhat. Just my personal experience after brewing Long Jing in the same Yixing literally 100s of times, then switching to porcelain/glass with improved results.

[Tead Off]

Chip, could be the yixing pot you used was just not the right one for the longqing. Hard to say without knowing what it was.

I also just rinse and pour boiling water through a yixing. If it is an old pot with ugly staining, I might scour and boil it, beginning anew. After all, when you start using any pot, new or old, you must begin again to brew the teas you want to in them and better to start fresh, IMO, as we don't know an old pot's history. Of course, if the exterior is wonderful, but, the interior is funky, a toothbrush with some cleanser or baking soda, then, several run through with boiling water should do the job.

[t4texas]

I do not know about Yixing, but Tokoname just needs some good rinsing with hot water before first use. Hagi on the other hand could require some initial soaking, and it is recommended.

Yixing is such a different animal altogether. I do not brew Chinese greens in Yixing anymore, prefering either glass method or porcelain. My personal experience was that Yixing seemed to mute Chinese greens somewhat. Just my personal experience after brewing Long Jing in the same Yixing literally 100s of times, then switching to porcelain/glass with improved results.

Have you brewed Chinese greens in unglazed Tokaname pots?

[Chip]

I do not know about Yixing, but Tokoname just needs some good rinsing with hot water before first use. Hagi on the other hand could require some initial soaking, and it is recommended.

Yixing is such a different animal altogether. I do not brew Chinese greens in Yixing anymore, prefering either glass method or porcelain. My personal experience was that Yixing seemed to mute Chinese greens somewhat. Just my personal experience after brewing Long Jing in the same Yixing literally 100s of times, then switching to porcelain/glass with improved results.

Have you brewed Chinese greens in unglazed Tokaname pots?

Many moons ago in that first kyusu I mentioned previously. But then again, I brewed just about anything and everything that was not flavored/scented it.

[Intuit]

According to the TeaMasters blog, repeat cycles of hot/cold water for conditioning unglazed teapots is as good as the traditional method (boiling). What you're after is unblocking small pours (read: loosening minor dust debris) through what I guess is rapid thermal transitions at the interior surface.

After reading up on the history and mechanics of Tokoname and Banko teaware manufacturing, I suspect that the function of these high-temperature (sintered) clays is not so different from that glazed vessels, in terms of brewing results for greens, be they Japanese or Chinese.

The wall surface pore are pretty small. These are strong, lightweight teapots. I'll bet they ring when you thwack them. As Chip says, heating of these teapots may or may not be required for various teas. So heat retention isn't a huge issue here (would be if they were thicker walled, but we wouldn't want that quality for delicate greens).

You look over the many Tokoname and Banko kyusu vendor websites, they don't even mention if the insides are glazed or not. Photos provided are clearly intended to display the internal filters employed. Vendors will wax poetic on the aesthetics (rightly so, may beautifully functional designs) and the points of various wall metal mesh or ceramic spout filter designs. But you don't see a peep about whether internal glazing is an issue or not.

Methinks the impact is relatively minor. Think about the minimal processing of these teas. Now what do you think is leaching out here??

We're not capturing large, late eluting phenolic complexes - they're not released from these teas, as they would be from oxidized oolongs.

Maybe...big IF here...maybe they are small, charged, readily soluble (early-eluting) components that are a bit bitter. They might be loosely bound - partially absorbed - and thus retained briefly to sort of spread their elution peak out over the serial extractions, lessening their impact in early infusions.

That may explain the 'smoothing' effect of an unglazed interior surface.

Pure conjecture here. Just running some thoughts on this interesting topic.

[clareandromeda]

my unglazed banko makes my greens taste sweeter with less astringency! my 2 cents.

[Oni]

+1, I noticed the same with mine.

[Intuit]

Yeah, but it's not likely that your banko purple clay pot is being 'seasoned' as you claim in another thread, CA.

Purple Banko-clays are reported to be iron-rich and produced under reducing kiln conditions. Water brewed in unlined iron reduced iron tetsubin is also said to make certain teas (non-oxidized) taste 'sweeter'.

Certain types of low dissolved mineral spring (groundwater) and mountain surface waters are also claimed to taste sweeter.

Whether this effect is caused by small amounts of iron released into iron-deficient water that makes it taste better, or physical reduction of flavor chelating minerals (precipitation), or chemical binding of undesirable elements, who knows?

Generally speaking, low iron water tastes better, dissolved iron higher than 0.3 mg/L imparts a bitter flavor to water. It's an aesthetic (taste and odor) water quality specification in the US.

Hojo (not exactly an authoritative source) claims that an iron tetsubin changes the cluster size of water and increases mineral-type reactions with polyphenols.

http://hojotea.com/categ_e/tetsubin.htm

It would be interesting to see if green tea brewed with water from a Banko *clay kettle* (and tea infused in an unreactive glazed kyusu) produced the same 'sweeter' tea result.

Hojo recommends using a unlined iron tetsubin for boiling water and a purple clay teapot for brewing green, white, yellow and flower teas.