Cleaning rings of tea stain on unglazed clay

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LeoFox
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Thu Jul 15, 2021 5:33 am

I was wondering what people do to clean those unsightly tea stain rings without resetting the pot or impacting the seasoning. In other words: spot cleaning

To make this post more useful, I am going to test various methods that have been suggested to me on my kobiwako shibo that has recently developed a tea stain ring from extended infusions with a natural baozhong:
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Methods suggested to me so far includes:
  • Citric acid either in powder form or lemon peel (by @@maple. This should be a relatively gentle method. There is some risk of the citric acid being absorbed by the clay and impacting the seasoning, but it should be relatively mild
  • Ground walnut shell powder with either finger or magic eraser (from my tea master). This should have very low risk of absorption but possibly some risk of eroding the natural texture of the the surface
  • Tea seed powder. This is supposed to be a traditional way. No idea where to get this material so won't try it but am listing it here.
  • Spot application with baking soda. May damage seasoning. I will try only if no other choice
  • spot application with sodium percarbonate. Will definitely impact seasoning. Final backup



The test

Preclean:
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citric acid. Made a saturated solution of citric acid. Using a qtip soaked in the solution, I cleaned the upper right quadrant. As a control, I attempted to clean the lower area with a water soaked qtip. The difference is clear. The qtip with citric acid turned brown and the stain came off readily.
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Walnut powder: wetted the pot and rubbed rest of stained region with my thumb along with powder. This took great effort, but still worked.

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Conclusion: both citric acid spot clean and walnut powder rub works. Walnut powder takes more effort while there is some risk of citric acid absorption.
Last edited by LeoFox on Tue Jul 20, 2021 7:31 pm, edited 7 times in total.
maple
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Thu Jul 15, 2021 10:12 am

in this case, you should try lemon acid
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LeoFox
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Tue Jul 20, 2021 7:04 pm

Updated post. Hopefully will be informative. Thank you,@maple
faj
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Tue Jul 20, 2021 7:15 pm

LeoFox wrote:
Tue Jul 20, 2021 7:04 pm
Updated post. Hopefully will be informative. Thank you,maple
Let me suggest a lazy man's solution that, I think, might work well for a case like this where the stains are near the top. Never tried it though.

Preheat a plate or bowl with boiling water, empty it, and then add just enough water so that if you dip the teapot upside down the water reaches the stains, but not the seasoning to be kept. Add a bit of percarbonate, then put the teapot upside down and wait a few minutes.
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LeoFox
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Tue Jul 20, 2021 7:25 pm

faj wrote:
Tue Jul 20, 2021 7:15 pm
LeoFox wrote:
Tue Jul 20, 2021 7:04 pm
Updated post. Hopefully will be informative. Thank you,maple
Let me suggest a lazy man's solution that, I think, might work well for a case like this where the stains are near the top. Never tried it though.

Preheat a plate or bowl with boiling water, empty it, and then add just enough water so that if you dip the teapot upside down the water reaches the stains, but not the seasoning to be kept. Add a bit of percarbonate, then put the teapot upside down and wait a few minutes.
Faj :lol: :lol: you really love percarbonate!
faj
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Tue Jul 20, 2021 7:30 pm

LeoFox wrote:
Tue Jul 20, 2021 7:25 pm
Faj :lol: :lol: you really love percarbonate!
I would not call that love. I would call that deep respect for something that works well, quickly, and with a minimum of fuss. :)
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LeoFox
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Location: Washington DC

Tue Jul 20, 2021 7:33 pm

faj wrote:
Tue Jul 20, 2021 7:30 pm
LeoFox wrote:
Tue Jul 20, 2021 7:25 pm
Faj :lol: :lol: you really love percarbonate!
I would not call that love. I would call that deep respect for something that works well, quickly, and with a minimum of fuss. :)
The citric acid spot clean was actually very easy hahaha.
faj
Posts: 636
Joined: Mon Oct 14, 2019 6:45 am
Location: Quebec

Tue Jul 20, 2021 7:50 pm

LeoFox wrote:
Tue Jul 20, 2021 7:33 pm
The citric acid spot clean was actually very easy hahaha.
You lost me at "rubbing with a Q-tip"... :lol:
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