TeaChat

Chip wrote:
However I will say this, I use Tokoname extensively and feel I brew in them as well as is possible for a mere mortal. I have brewed in a much more limited basis with the Bizen with at times better results than the Tokoname. Why?

Is it a psychological thing, is it density factors, is it general clay thickness/heat retention issues ... or is it that Bizen has a "magical" effect on water as touted? As also touted by Banko and now also Shigaraki vendors and users?

I am continuing to access all factors. Now I need some Banko and Shigaraki as well.

Its the Magical effect! Bizen is just so Primal-cool...
I have a Yunomi..and Houjin...NOW I need a Magical Kyusu....

JBaymore wrote:Chip,

Since greens are known to be SO sensitive to brewing water temperature alone.........

Might the differences be attributible to the more rapid cooling or heat retention differences between the two different kyusu........ due to tthermal condustivity of the clay, wall thickness, surface area, and so on and not have anything to do with the H2O chemistry actually reacting with the clay surface in any way?

My "science background" causes me to think about identifying and controlling variables before making conclusions.

best,

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

wondering about the tannic acid in various tea. what sort of reaction does tannic acid have with various metals like iron, aluminum, alumina, manganese dioxide, kaolins (high alkali (british grolleg) vs. low alkali (american georgia grolleg) and more evident in various clay bodies ?

the above are variables that are in direct contact w/ the actual tea.

not to mention pH levels of minerals / metals, etc in the brewing water...

i drink shincha and matcha primarily. i'm a novice in other kinds of teas.

my quest recently has lead me to a similar path about how different clay bodies react with nihonshu. in the next year, working w/ some nihonshu sommelier. we're doing a taste test w/ glass as the control and a dozen different bare clay bodies and the taste differences.

call me nuts.. but as unrefined as my palate is, i 've noticed changes in flavor from the same bottle of nihonshu using various different high fired unglazed clay bodies and glass... taste testing, same time pours, similar shaped vessels (oxidation) etc.

this is something that has intrigued me in addition to fired clay and the reaction with red wines etc.

thoughts ?

oh, also side note. stop thru the fantastic show at Musee Tomo in tamaike sanno (akasaka) tokyo. amazing. if u have a chance to see the catalog, the pieces are amazing. wild ! i wish i could handle the pieces to get a better sense of balance.

cheers,
cory

In the Same but Different department.
Among beer aficionados here in Japan unglazed beer cups sell for a premium. If you want a full head of foam a glass can't compete. My understanding is the "open" surface of unglazed clay creates a turbulence that spins the liquid as it is poured. I have noticed a similar but not as dramatic effect with the black glaze I fire. I fire only with wood so there are a lot of areas that will cause this type of 'spinning' of liquid as it is poured. Beer does taste different if enjoyed out of a unglazed cup. I would think tea would be affected too but I usually drink tea out of kohiki, white slip ware, cups. Since they are glazed they don't produce as much turbulence.
Dave

Hi Chip, this is very interesting field for research...

I can add to BonJiri and Togei words that important is also atmosphere of firing, the temperature vs. clay, time and style of firing. I mean that for example Potters know that if you fire to lower temp. for longer time so felling is different from higher temp.in fast firing. And "the felling" is not only impression from pot but also difference in structure of surface and body of the pot so we can see different influence on tea especially on fragrances. My opinion is that there is not "good and bad" but that certain piece (material, glaze-unglazed, firing, shape and so on) is better for certain tea (in some cases for teas generally)

On one hand As potter and tealover I have opportunity to try different clays and firings with different teas but on other hand I have to be focused more on creating pots (as time is limited:) so it is great when some customers helps with it and try our clays. For now I try make more unglazed teapots and I love the reactions between clay and tea but I am on beginning...

Here is interesting post on this topic:http://teamasters.blogspot.com/2010/01/ ... iment.html

Best
Petr

Very interesting read Petr, I am excited for your next firing. I hope it goes well for you. Im also looking forward to my new pieces, since we spoke of unglazed shiboridashi. Im curious of the reaction of your natural clay and tea brew.

Cheers
Jose

I think this is a new question for this topic, although I am sure it has been touched on elsewhere: what considerations should I have in mind for cleaning my fine handmade teawares, especially those with either exposed unglazed surfaces, or with crackled glazes?

As I expand my collection of fine cups, I will not be the only one drinking from them, so I need to be more careful about hygiene (I work in a hospital, it's an occupational hazard), and I expect to share my cups with visitors who use variable types and quantities of lip balms and makeup. So I not sure I can trust just a rinse with hot water and wipe with paper towel.

Interesting topic!

I do use very hot water (more of a soak than a rinse), this cleans and sterilizes ... and speeds thorough drying (which I consider hypercritical). I think. Also, no make up, balms, scents touch most Hagi here.

Taking this into a hospital setting adds some interesting elements.

I'm not using it with patients, but sharing it with other staff who from time to time will have sniffles and colds, and are very sensitive to risks of disease transmission (we've all got bottles of hand sanitizer on our desks), and cannot be expected to wash their face before they touch my teaware. I would like to have something nicer to offer than styrofoam cups and mass produced teawares, and ideally, as nice as what I am drinking out of myself.

Hello, I am a new member, I am a potter living in Eugene, oregon. I have been a potter for about 7 years, and am just starting to make tea wares, and learning about the way of tea. I am really interested in local materials, as well as how the clay influences the tea. I have found some really nice deposits of red/purple clays here in our volcanic area, some very similar to Banko pots. I am very curious about the difference between reduction fired vs. oxidation fired teapots, as well as firing temperatures influence. I have clays that can easily withstand 1260 degrees, and was curious if it is bad to fire this high. Anyone have thoughts on this? Also, any thoughts on reduced vs. oxidized? One thing I haven't seen discussed is that if you get iron hot enough, even in oxidized firing, it naturally decomposes to reduced form, is this the same effect? Looking forward to some interesting conversations.

Jayme Allen
Eugene Oregon

1260 F or C?

Hi Jayme,

If you haven't already, you might want to try to contact longtime Eugene potter Hank Murrow as he is extemely knowledgeable about your local materials/their firing characteristics. If you don't have his contact info, kindly PM me and I'll try to connect you.

Best,
R

That is 1260 C (2300F). I am more concerned with the "melting" of the iron here, vitrification levels can always be adjusted by raising alumina in body, and it can always be opened with sand as well.

Ronin- I have met Hank a few times, we somewhat know each other, maybe it's time for me to bug him a little more.

Thanks,
Jayme

Hello,
I would like to ask the artisans too.
I have made a kiln full of porcelain teapots and cups I am about to fire. I have used 2 types of porcelain. The first is a typical 'porcelain', the other is a mix of white sandy clay from Kyoto, hand dug, and Amakusa porcelain. I am planning on firing everything unglazed.
My question is; will unglazed porcelain, fired to about 1250-1300, (I don't use a probe), be good for the taste of tea? I am hoping to get some benefit from using an unglazed body.
Dave

On a note related to Hank Murrow.
I did a paper in June of this year on how much carbon wood firing puts into the air. I got solid data from Hank on how much wood he uses.
If anyone is interested in reading the paper it is accessible here, http://wp.me/p6ult-1lr

Other blog posts related to the paper are accessible here, http://wp.me/p6ult-1iy
http://wp.me/p6ult-1iW
http://wp.me/p6ult-1jm
http://wp.me/p6ult-1jt

I can't help but feel that porcelain fired to those temperatures is going to be very vitreous, and will be much like glass. This will possibly not influence the tea much, but it should show the color amazingly. I often work with porcelain, but haven't tried unglazed bowls, so please let me know if you get something good. Also, from discussions I have read, it is the iron that influences the tea, so the one with the dug clay might get some results, but the plain porcelain is almost iron-free. Out of curiosity, why do you blend the dug clay with the porcelain? It might provide more effect if used by itself. Please let us know what you end up with regardless of good or bad.

When I have time, I'll look through your article more, it is definitely a hot topic of our generation. A thought that I have had is, especially being here in the middle of lumber industry, is firing with sawdust, which is a commercial by-product, and could probably fire more efficiently that wood based simply on fuel to air ratio due to the small size of the saw dust compared to larger pieces of wood. Since the lumber industries harvest in a sustainable way (I think), we are then as well simply by proxy.

Best of luck with your firing!

Jayme

Hello Jayme,
Thank you for your reply.

Out of curiosity, why do you blend the dug clay with the porcelain?

The porcelain is a traditionally processed body from Kyushu. It doesn't match my glazes so I would have to either alter my glazes or not use it. I decided on mixing it since the body from Kyoto is extremely difficult to throw pure and I had a ton of each on hand.
I will post some pictures after I fire. I did post a few pictures of both bodies on my blog a few hours ago, have a look see if you like, http://wp.me/p6ult-1PT
Dave