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Apr 19th, '10, 12:45
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What is this weird gunk on the inside of my Tetsubin?

by Abracadaver! » Apr 19th, '10, 12:45

A while back I posted about white build-up in my unused tetsubin. The original topic is here: http://www.teachat.com/viewtopic.php?f= ... 4&p=124865

Last night, I finally got around to rinsing and prepping my tetsubin. Why did it take so long? A variety of uninteresting reasons, but I decided that it was well past time for me to start using it.

A little background on the kettle before I continue:
I purchased it from a Japanese ceramics shop in Santa Monica a couple of years ago (which has since closed). I was told by the sales clerk that it was new, from Japan, and was for stovetop use (no interior coating). He did not know the manufacturer, but the price was on par with other uncoated tetsubin(s?) that I've seen. Besides, I figured it was a pretty safe bet as they had one of these kettles for daily shop use. Prior to last night, I had never put any water into the kettle and it has not come into contact with any water since it has been in my possession.

I followed the prepping instructions on Hojo's site: http://hojotea.com/categ_e/tetsubin.htm
The first few rinses before boiling were cloudy, and I began boiling water in the kettle only after the water rinsed clear. I boiled the water using a Waring hot plate.

Almost immediately, little bits of the coating on the handle began flaking off. A bit disconcerting, but not a big deal.

With each round of pouring out the water and boiling fresh water, I would see little black flakes in the water. After six or so rounds of this, I let the kettle air dry (per the recommended methods). There is still a white coating on the interior, along with a few rust spots here and there making me think that the kettle has been used before. Seeing the photos, does this seem to be the case?

Looking closer in the bone-dry kettle, I saw these wet-looking patches with flaky/ashen appearing edges that seem to be the source of the black flakes. What is this stuff? Is it safe? Can it be scrubbed out?
!??!??!?
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Apr 19th, '10, 13:00
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Re: What is this weird gunk on the inside of my Tetsubin?

by tsusentei » Apr 19th, '10, 13:00

Hi Abra,

Having spent many years in Japan, I have seen every kind of yucky looking tetsubin imaginable, but yours doesn't look very used. But first some questions to ascertain its condition:

Is the interior substance tacky or dry?
Is there any calcification on the exterior around or beneath the spout?
The water pours clear, but does the water taste bad/funky?

I did not see significant rust in your pictures, what there is is probably just from ambient humidity. I have seen some pots rusted right through from years of non-use. The black flakes are likely nothing to worry about.

I would love to see the exterior of the pot if you have the time. And the flaking handle, as well.

What we would always do in Japan after buying a pot of ambiguous origins was stuff it full of potatoes and boil the crap out of it. Empty the potatoes and rinse/wipe out several times. Boil until clear and use. But let me know your answers to the above before you proceed, if you have the time. Good luck!

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Apr 19th, '10, 13:21
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Re: What is this weird gunk on the inside of my Tetsubin?

by Abracadaver! » Apr 19th, '10, 13:21

Hi Tsusentei,

Thanks for taking a look!

I'll post the photos that you requested later today. In the meantime, to address your questions:
The spout seems clean. I wouldn't have thought for moment that the kettle had been used, if not for the minor rust spots and the chalky almost scale-like interior look.
The water tasted fine, a little trace taste that I can't put my finger on, but certainly not foul.
The dark patches on the interior are not sticky, but if I scrape a bit with my finger, a little flakes off.

You say that the black flakes are likely nothing to worry about, which is a relief, as my biggest concern is ingesting something nasty. Any thoughts on what it might be?

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Apr 19th, '10, 14:10
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Re: What is this weird gunk on the inside of my Tetsubin?

by tsusentei » Apr 19th, '10, 14:10

The little trace of something is probably iron or possibly the chemical that was used to seal the pot against rusting. This chemical is not usually harmful, but you do want to clean it out thoroughly to get the best tasting water possible for your tea.

The discoloration/scaliness is likely some form of oxidation/rust. If you follow the "potato method" your pot should taste much better and nothing of consequence will remain. After each use place it, still warm, upside down to dry or pat it out with a clean towel that is reserved for that purpose. My kettle is supposedly from the bakufu era (13th century), and still looks and works great, so your pot should serve you well for many years to come.

Looking forward to your pics!

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Apr 19th, '10, 14:11
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Re: What is this weird gunk on the inside of my Tetsubin?

by Tead Off » Apr 19th, '10, 14:11

It very well could be a thin coating of urushi (lacquer) that was added to the tetsubin for protection against rust. I would try and remove all of it with a sponge that has a reverse side with a scrubber.

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Re: What is this weird gunk on the inside of my Tetsubin?

by Abracadaver! » Apr 19th, '10, 22:10

Thanks for all of the info, guys. Here are the photos. You can see where the coating has flaked off of the handle. The dark areas on the handle are where the coating flaked off--the coating looks like it's meant to match the copper lid. Each time I would lift the lid to check the water, the little bit of steam that hit the handle would cause the coating to flake.

Tead Off--would urushi be used to spot treat the interior of a kettle?
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Apr 19th, '10, 23:26
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Re: What is this weird gunk on the inside of my Tetsubin?

by Tead Off » Apr 19th, '10, 23:26

Not sure why they would put urushi on the handle except maybe for cosmetic reasons but seems odd. I don't think they used urushi to spot treat tetsubin, only as a rust deterrent inside, but, maybe the whole pot was coated with it originally. You should write to Hojo or someone else that is intimate with tetsubin and their construction.

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Re: What is this weird gunk on the inside of my Tetsubin?

by Oni » Apr 22nd, '10, 02:05

When I got my tetsubin, it had a white powder on the inside, just take a piece of soft paper and wipe it out, it is a grey powder, wipe it clean a few times, and boil water at full capacity 3 times over with new water each time, and wipe it again, after a few weeks it will turn shiny blueish grey on the inside, something ore like shine, if it gets that metal color, no build up will form, Horaido wrote me that some anti rust protective measures are taken with new unused tetsubins, but after boiling water five times it should be safe to use. Your tetsubin looks very good, mine also has a layer of urushi at the joints, but that is nececary, where was it made, where have you bought it?

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Apr 22nd, '10, 14:27
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Re: What is this weird gunk on the inside of my Tetsubin?

by tsusentei » Apr 22nd, '10, 14:27

Hi Abra,

Very beautiful pot! I think it will last you many years and give you limitless enjoyment.

Aaron

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Apr 22nd, '10, 17:35
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Re: What is this weird gunk on the inside of my Tetsubin?

by tsusentei » Apr 22nd, '10, 17:35

Someone asked me to post pics of the kettle I mentioned earlier, so here they are. The first 3 are stereoscopic, to allow a better view of the details, then there are a few of the interior/spout, etc. There are no pics of the lid because the one that I use is not original. The original lid for this pot was likely made of the same cast iron and probably rusted away many years ago. I use an old lid from a chagama and am always on the lookout for a lid I like.
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What do you think? Thanks for checking it out!

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Apr 22nd, '10, 21:11
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Re: What is this weird gunk on the inside of my Tetsubin?

by IPT » Apr 22nd, '10, 21:11

That's a beautiful Tetsubin! Is it possible to get lids made? Or is it possible to find lids without pots?

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Re: What is this weird gunk on the inside of my Tetsubin?

by Poohblah » Apr 22nd, '10, 23:56

When you cross your eyes, the stereo images appear to be 3D. I can realize the texture much better when I do that. Fantastic!

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Re: What is this weird gunk on the inside of my Tetsubin?

by tsusentei » Apr 23rd, '10, 02:55

IPT wrote:That's a beautiful Tetsubin! Is it possible to get lids made? Or is it possible to find lids without pots?
Thanks! I like it very much. It likely is possible to have a lid made, but I am sure that it costs more than I either have or am willing to pay. Lids on their own are out there, but only in Japan and only, generally, at outdoor antique bazaars, etc. I have a few just because I have bought them hoping for a good fit, but haven't found it yet.
Poohblah wrote:When you cross your eyes, the stereo images appear to be 3D. I can realize the texture much better when I do that. Fantastic!
I know! That is why I include images like that. Much easier to tell what is going on with the design :) Thanks for noticing.

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Re: What is this weird gunk on the inside of my Tetsubin?

by Abracadaver! » Apr 27th, '10, 17:35

Thank you all for your help and input. I will be boiling potatoes in my kettle tonight.

tsusentei, that is a beautiful tetsubin...

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Apr 27th, '10, 17:45
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Re: What is this weird gunk on the inside of my Tetsubin?

by tsusentei » Apr 27th, '10, 17:45

Abracadaver! wrote:Thank you all for your help and input. I will be boiling potatoes in my kettle tonight.

tsusentei, that is a beautiful tetsubin...
Thanks, right back at you!

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