Raku

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debunix
Posts: 249
Joined: Sat Oct 21, 2017 1:27 am

Thu Mar 29, 2018 10:48 am

What's the inside of that charming guinomi like?

I've only got one raku bowl myself, which was a gift, and I'm keeping it strictly for occasional use with Matcha, simply because I don't know its history.
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steanze
Posts: 290
Joined: Mon Oct 09, 2017 4:17 pm

Thu Mar 29, 2018 12:02 pm

debunix wrote:
Thu Mar 29, 2018 10:48 am
What's the inside of that charming guinomi like?
Easier said than done, this thing is shinier than a mirror :D Here are a few more pics. Basically, even though it's hard to see, the inside color and texture is similar to the outside, maybe just with a little bit less red. I took these pictures in the shade but even then...
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debunix wrote:
Thu Mar 29, 2018 10:48 am
I've only got one raku bowl myself, which was a gift, and I'm keeping it strictly for occasional use with Matcha, simply because I don't know its history.
Yes, this is the only raku I have too, mostly out of concern for the lead.
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chamekke
Posts: 9
Joined: Sun Mar 25, 2018 5:49 pm
Location: British Columbia, Canada

Sat Mar 31, 2018 1:17 pm

Fuut (and everyone), your posts about Raku are wonderful. Please keep sharing as much as you like!
steanze wrote:
Thu Mar 29, 2018 12:07 am
I have a question about Raku that perhaps you can answer. I know that traditionally Raku glaze contained (and leeched) lead. Are contemporary potters still adding lead to their glazes? I have heard of some lead-free Raku, but I wonder whether that's how all Raku is made nowadays, or whether there are still many pieces with lead. Thanks!!
steanze, traditional Japanese raku does include some lead, although not a great deal. In tea ceremony, matcha is prepared and drunk off almost immediately, so there is too little time for any lead to leach into the matcha. That's what they say, anyway.

I'm going to quote Joseph Justice, of the late lamented Tea Toys site, on the subject of Raku wares:
The rakuware [in Japan] is made with a tiny proportion of lead to make the glaze melt at the low temperatures rakuware is fired at (approx. 1000 C for black; 800 C for red; “real Raku” is fired at 1200 C and 1000C respectively).

When using a red rakuyaki bowl for koicha, be careful (before class) not to wipe the bowl with the chakin too strongly. I have seen a red rakuyaki bowl lose a whole side in the grasp of a male student! It is sometimes, falsely, said that red raku will melt in hot water; I do not think that is true but red rakuyaki are very soft.

The only danger from lead in any glaze comes with prolonged holding of an acid liquid in the utensil, which will leach out the lead. This should NEVER happen in a rakuyaki teabowl, since the matcha is not acid in nature and it is in the bowl for such a short time.

One way to help keep the bowl clean in the pores is to soak the bowl for about 5 minutes before using. I heard this directly from the present Kichizaemon 15th himself. Especially in winter, if you use hot water, the bowl will not absorb the heat from the tea and even the last guest will get a drink of hot tea; too hot and the poor shōkyaku [first guest] can hardly drink it much less savor the flavor, so finding just the right temperature requires much experimentation. Soaking too long is a bad idea, I can say from personal experience, because the “special smell” of the clay becomes too strong.

After using a rakuyaki bowl or any utensil, it takes several days for it to dry out again. Leave the bowl right side up, in the shade, on absorbent towel or paper. The water will soak through so have something that won’t be affected underneath.

If some rakuyaki mukōzuke dishes for kaiseki should come into your hands, the same principles apply; soak with water before using to prevent the sauce from soaking into the ceramic. In Japan the rainy season in June brings the danger of mold developing in the pores where there is the slightest trace of organic matter or water so you really need to dry things out. Heating gently might be possible but it is dangerous for valuable works.

Needless to say, you SHOULD NOT use vinegar or citrus juice of any kind to make the sauce.
Lastly, American raku should generally be regarded as unsafe for food consumption. Not just because of the lead, but also other metals that give it that glorious iridescence. I believe the clay is more porous than Japanese raku, too, which would encourage greater leaching. I understand that some potters have made lined or "food-safe" American raku vessels, but personally I would play it safe and not eat or drink from them.

Edited to gloss the word shōkyaku ;)
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Elise
Posts: 74
Joined: Tue Dec 12, 2017 2:22 pm

Sun Apr 01, 2018 2:15 am

steanze wrote:
Thu Mar 29, 2018 12:07 am
Fuut wrote:
Sun Mar 25, 2018 7:51 am

I wanted to share another raku bowl, one that is quite special because of the chance effects that were set in the glaze. This bowl has quite the 'haki'. For which I'll quote someone from another forum who explained it to me once, albeit in a different setting (togosu - metal fittings for the making of koshirae, the formal fittings for japanese swords). Please read the following. The discussed item; a tsuba is a sword guard for a sword. Owari the province said fitting was made in.
Wonderful piece! I have a question about Raku that perhaps you can answer. I know that traditionally Raku glaze contained (and leeched) lead. Are contemporary potters still adding lead to their glazes? I have heard of some lead-free Raku, but I wonder whether that's how all Raku is made nowadays, or whether there are still many pieces with lead. Thanks!!
Lead has always been part of ceramic glaze composition. It is widely used in low temperature glazes, like Raku for instance. There have been regulations internationally adopted since the 1970’s concerning lead (among other substances) leakage acceptable measures in large-production ceramics for food use[*]. When mentioned in production now, you can find « lead free » or « lead safe » production, the last one means that lead leakage has been tested and fits in the rates accepted by current regulation.

For now, the problematic items would be low temperature ancient pieces as well as contemporary ceramic for food or drink use made in developing countries and/or by small artisans less likely to be tested for lead leakage. I mention developing countries because as lead lowers fusion temperature, it’s rate can be increased in order to lower firing costs. Then lead is found in higher proportion in the glaze and at the same time underfired and more likely to leak

What you should specially avoid is storing food for a long time or put acidic food, like vinegar pickles, in such ceramic items. But I guess it’s not likely to happen in a Raku chawan ;)

For general informations and recommandations, please read the following article:
https://cchealth.org/lead-poison/pdf/ceramics.pdf

[*]Japan: Food Sanitation Law, Law No. 233, December 24, 1947, et seq., Specifications and Standards for Food Additives, No. 370, 12/18/59
(JETRO 2010 version )
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steanze
Posts: 290
Joined: Mon Oct 09, 2017 4:17 pm

Sun Apr 01, 2018 6:47 pm

Thanks for the information Elise!
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Fuut
Posts: 32
Joined: Thu Oct 26, 2017 8:31 am

Mon Jun 25, 2018 5:15 am

AtlasRisen wrote:
Tue Jan 02, 2018 8:12 pm
Very beautiful! I quite like the one by Utsushi - Shoraku Sasaki (3rd)
Here's mine by Shoraku III

This is why everyone should upload to teaforum instead of link from a image hosting site :lol:
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