Why is my sencha so astringent when brewed in this kyusu?

[Milo]

I bought a Shofu banko kyusu from Thés du Japon recently. (http://www.thes-du-japon.com/index.php? ... cts_id=238) It's beautiful, incredibly light, perfect pour, functional—everything I'd want in a banko. Everything that is, except for one thing: the taste of the sencha brewed in it.

I'm not sure how it was fired but judging by its steel-violet interior, it appears to have been reduction-fired. By contrast, the banko kyusu I have from O-Cha is a rich terra cotta red which, if I'm not mistaken, suggests it was oxidation-fired (https://www.o-cha.com/fukamushi-teapot- ... ory_id=164). The sencha brewed in the latter kyusu is wonderfully soft, rich, and aromatic. However, I have brewed hundreds of cups of sencha in this one, so I don't know whether these optimal results are from its firing method it being well-seasoned.

The sencha brewed in the Shofu, however, is mouth-drying astringent. In fact, it's been fifteen minutes since I finished my second steep and my mouth still feels dry. But again, I don't know if this is due to its firing method or it being a virgin (i.e. non-seasoned) kyusu.

Any one have any insight on this contrast in results?

[kyarazen]

I bought a Shofu banko kyusu from Thés du Japon recently. (http://www.thes-du-japon.com/index.php? ... cts_id=238) It's beautiful, incredibly light, perfect pour, functional—everything I'd want in a banko. Everything that is, except for one thing: the taste of the sencha brewed in it.

I'm not sure how it was fired but judging by its steel-violet interior, it appears to have been reduction-fired. By contrast, the banko kyusu I have from O-Cha is a rich terra cotta red which, if I'm not mistaken, suggests it was oxidation-fired (https://www.o-cha.com/fukamushi-teapot- ... ory_id=164). The sencha brewed in the latter kyusu is wonderfully soft, rich, and aromatic. However, I have brewed hundreds of cups of sencha in this one, so I don't know whether these optimal results are from its firing method it being well-seasoned.

The sencha brewed in the Shofu, however, is mouth-drying astringent. In fact, it's been fifteen minutes since I finished my second steep and my mouth still feels dry. But again, I don't know if this is due to its firing method or it being a virgin (i.e. non-seasoned) kyusu.

Any one have any insight on this contrast in results?

generally iron rich reduction fire pots do add that astringent/bitter edge... this is quite apparent if you compare oolong teas in lets say an yixing that is oxd fired, and something like a shigaraki from masaki tachi.. you will get more forward aromatics at the expense of mouth feel.

for an experiment you can consider brewing some sencha in equal ratios in both pots and then leave a small cup of each to aged for a few hours up to 12 hours.. and you can monitor the color change over time.. pots leaching iron into the water.. the tea will darken and blacken faster...

[victoria3]

Great idea a side by side comparison. Would love to see results. Same; water, time of day, temperature, time for your body to taste. You may have to reserve the reduction fired pot for specific teas like Pu-erh tea or stronger darker greens.

[Tead Off]

I bought a Shofu banko kyusu from Thés du Japon recently. (http://www.thes-du-japon.com/index.php? ... cts_id=238) It's beautiful, incredibly light, perfect pour, functional—everything I'd want in a banko. Everything that is, except for one thing: the taste of the sencha brewed in it.

I'm not sure how it was fired but judging by its steel-violet interior, it appears to have been reduction-fired. By contrast, the banko kyusu I have from O-Cha is a rich terra cotta red which, if I'm not mistaken, suggests it was oxidation-fired (https://www.o-cha.com/fukamushi-teapot- ... ory_id=164). The sencha brewed in the latter kyusu is wonderfully soft, rich, and aromatic. However, I have brewed hundreds of cups of sencha in this one, so I don't know whether these optimal results are from its firing method it being well-seasoned.

The sencha brewed in the Shofu, however, is mouth-drying astringent. In fact, it's been fifteen minutes since I finished my second steep and my mouth still feels dry. But again, I don't know if this is due to its firing method or it being a virgin (i.e. non-seasoned) kyusu.

Any one have any insight on this contrast in results?

generally iron rich reduction fire pots do add that astringent/bitter edge... this is quite apparent if you compare oolong teas in lets say an yixing that is oxd fired, and something like a shigaraki from masaki tachi.. you will get more forward aromatics at the expense of mouth feel.

for an experiment you can consider brewing some sencha in equal ratios in both pots and then leave a small cup of each to aged for a few hours up to 12 hours.. and you can monitor the color change over time.. pots leaching iron into the water.. the tea will darken and blacken faster...

This is not my experience with Banko kyusu. I have 5, but I effectively use 3 of them of varying size. 2 are thinner walled and one is a heavier, thicker hohin. Of the 2 thinner walled pots, one is probably a good 30 years old and the other is maybe 6 or 7 years, a Masaki Tachi product. I love the 30 year old one best as it seems to produce very smooth, balanced brews with sencha and the occasional gyokuro that I make in it.

Do these pots make a tea more astringent than let's say a Bizen pot that I have. Definitely no, and the Bizen is oxidation fired. Same when compared to Yixing pots using the same tea. In fact, I found the Banko pots also very good for sheng puerh.

With the right brewing and leaf to water ratio, astringency can usually be controlled. Size of pot and leaf amount used can also give unusual astringency. And, since this is the season of Shincha, Shincha are notorious for extra astringency.

So, to answer the OP's question, other than what I wrote above, I have no idea why this pot is giving you problems. It's possible it wasn't fired properly or the tea selection just didn't work, or something that you're doing may be the cause. I would tell Florent about your experience and see what he says. I'm sure all Banko pots are not the same, but this sounds odd to me.

[jayinhk]

What volume are the two pots concerned, and how much leaf are you using in each?

[kyarazen]

I'm sure all Banko pots are not the same, but this sounds odd to me.

like you've said.. not all banko, nor bizen pots are the same. bizen's aesthetics come from cyclic oxidation/reduction in the long duration firing (traditionally wood fired for a week+). there will be some that's more "reduced" and some items that end up more "oxidized" from the firing. similarly, it uses iron rich clay, the final state from firing determines how much iron the pot will leach into the tea.

[Milo]

What volume are the two pots concerned, and how much leaf are you using in each?

The new one is 250 mL, the old one 360 mL. I use a 6 g : 250 mL ratio for sencha. For the first steep, I brew@ 160-160°F (kyusu pre-heated) for 90 seconds.

I like the idea of an A/B test. I'll do a blind one later today or tomorrow.

[jayinhk]

Since the new one is smaller, I think your problem is the kyusu is hotter because it heats faster. Try using slightly cooler water with the new one.

[TORamarn]

- Have you tried brewing another sencha in this Banko teapot?
- Have you tried brewing this sencha in a Porcelain teapot?
- Did you boil your new Banko?
- Try filling hot water in your new Banko, wait for a minute, pour out, and taste the water.