This instructional, which I originally posted in another forum, has been updated. Please share your methods of cleaning unglazed ceramic teaware.
As a tea drinker who uses a collection of vintage unglazed teapots, I have over the years found various ways to reset these pots. I have gone through each of the steps below, with good results, so thought I would locate the information in one area for everyone. After getting a very dirty old yixing pot I had to go one step further, so am sharing the whole process with you. Also, a few 60’s F1 pots had been stored in damp conditions without air for decades, these pots took several years to reset, simmering, air drying in the sun on a window sill, each year testing the water to see if progress was made. At that time I did not know about using Sodium Percarbonate for cleaning pots, it is possible had I used it resetting time could have been reduced to a few weeks. I have only done this with pots from 1960s forward, older pots may need even greater attention and care. If you have reset older unglazed pots, or very thin ones, please share what method you used.
*Caution: This is assuming your pot is not super fragile or very thin*
A. Awakening Old Yixing (old pot that hasn’t been used for a long time and needs resetting)
1. Place teapot in room temperature filtered or spring water for two days. Fully immerse teapot and lid in water.
2. On the third day put the teapot into a large stovetop pan, with a trivet and a towel wrapped around the bottom of the pot and lid. The cloth prevents rattling of the teapot and lid to the sides of the pot and each other when water is simmering. Simmer the teapot lightly for 30mins-1hr. Do not boil. Stay nearby to listen and make sure teapot is not rattling against the pan or lid.
3. Turn the power off and let the pot cool down overnight.
4. Next morning visually inspect the water. Does it look clean? If so, how does overnight water taste? If the overnight water looks and tastes clean, the pot may be ready to use, if not repeat A, or proceed to next step. Rinse pot with very hot water.
B. Resetting Old Yixing (dirty, smelly)
1. Put a large pan on the stove, with a trivet and a cloth lined inside. Fill pan 3/4 with filtered water. The pan should be large enough to completely submerge the teapot. To prevent contact rattling; place pot inside pan using cloth to separate it from metal and to separate lid from body of pot.
2. Bring the water to a high simmer, reduce heat to a simmer, and gently cook for 1hour.
3. Allow the water to cool with pot inside.
4. Discard water setting pot aside. Rinse pot with very hot water.
5. Refill the pot with filtered water, bring to a boil, and add a few tablespoons of tea leaves (whole leaf -not teabags or tea fragments) that are not fancy or leaves that you used a few times already. Turn off the heat, cover the pot and steep the leaves for 30 minutes. Strain out the leaves and return the teapot to the tea letting it rest overnight.
6. Wash pot with hot water, place pot in bowl, drench with very hot water and after a few minutes hand dry with soft cloth and place in sunny spot to thoroughly dry (like a window sill).
7. Fill teapot with just boiled filtered water, let cool overnight. Next day taste water, if distasteful repeat steps 1-6 several times and or proceed below to C.
8. If teapot water tastes fine, use cleaned teapot as a tea pitcher (with similar tea you intend to dedicate it to) for a week or two to reset pot.
C. Getting Rid of Discoloration in Yixing (if pot is still dirty, moldy or smelly then try the following)
1. Lightly scrub with Baking Soda, using non abrasive material so as not to scratch clay.
If pot is still not clean then;
2. Follow steps 1-4 in B. Resetting Old Yixing, and repeat these steps adding 3 TBS Baking Soda. Simmer for 1hr. After pot is somewhat cooled lightly scrub pot again, using non abrasive material so as not to scratch clay. Follow with a white vinegar (distilled vinegar) bath (to fully remove traces of baking soda) by soaking it in hot diluted white vinegar for about an hour before giving it a final soak in hot water. All traces of vinegar will evaporate within 24-48hrs.
D. Use Sodium Percarbonate if Discoloration & or Mold remains (If pot is still not clean)
I’m not using chlorine in this step because chlorine will not penetrate porous surfaces, only the water penetrates, while chlorine stays on surface, leaving mold's roots alive and eventually having mold return. Sodium Percarbonate is an oxygen based mild alkali bleaching agent, it releases hydrogen peroxide when dissolved in water, and has a strong fungicide effect. The active ingredients are sodium carbonate and hydrogen peroxide. It will not remove rust stains or mineral deposits from hard water. Percarbonate by-products are non-toxic and environmentally safe, but it should be used and stored OUTDOORS as it can cause irritation to the skin, eyes, and respiratory tract, and when in contact with flammable materials enhances combustion. Dispose of Sodium Percarbonate in the sink (it breaks down to oxygen, water and sodium carbonate/soda ash), Do NOT let this chemical directly enter the environment, such as placing in the yard or on plants. Please refer to product safety guidlines.
1. Put 1TBS Percarbonate into vessel large enough to submerge teapot into (like pyrex pitcher) & put 1TBS (+-20g) of Percarbonate into teapot.
2. Boil filtered water, pour approximately 1 Liter or less of the hot water (100-150 F) into teapot & holding vessel. Stir the mix. Place lid on teapot.
3. Let it cool 1-2 hours & lightly scrub (using gloves outside) where needed with toothbrush or nonabrasive cloth. Sodium Percarbonate remains active for 5-6 hours.
4. Rinse a few times with very hot water.
5. Put a large pan on the stove, with a trivet and a cloth lined inside. Fill pan 3/4 with filtered water. The pan should be large enough to completely submerge the teapot. To prevent contact rattling; place pot inside pan using cloth to separate it from metal and to separate lid from body of pot .
6. Bring the water to a simmer, reduce heat to a very low simmer, and gently cook for 1hour.
7. Discard water setting pot aside. Rinse pot with very hot water, and towel dry.
8. Let it dry completely preferably inside in a sunny spot.
9. Fill teapot with boiling filtered water and let it sit overnight. If no off taste is present then you can now use the teapot.
10. Use cleaned teapot as a tea pitcher (with similar tea you intend to dedicate it to) for a week to reset pot.
After boiling in Baking Soda some stains remained. After Sodium Percarbonate all stains are gone.
williammimi70 wrote: ↑Wed May 03, 2017 1:30 amThank youvictoria3 wrote: ↑Wed May 03, 2017 1:19 amPerfect, if you go to step 2 just make sure not to let the lid or pot rattle in the stove top pot-and protect with cloth or trivot and keep a watchful eye-ear.
I will be careful
Zared wrote: ↑Wed May 03, 2017 6:30 pmI did it years ago because everyone said we should. I don't see a point in doing it anymore. Now I just scrub an unused pot with warm water to remove any dust/clay. Then I'll over brew cheap tea in and it's ready to go. If it's dirty or moldy than I'll give it a bleach bath. Soak in fresh hot water a few times. I'll finish it with a tea soak.
I suspect the origins of boiling came about outta people's fear of using bleach.
victoria3 wrote: ↑Wed May 03, 2017 8:11 pmSeems we each have our own encounters with dirty, smelly, moldy pots. In my case, as you can see from the 1st before & after picture, there were years of solid residue and what looked like mold. I didn't want to take any chances with the mold so took the cleaning a step further than usual using Sodium Percarbonate to go deeper than Clorox bleach would. Clorox bleach will only remove mold on the surface, it does not penetrate a porous surface or reach out of site spores & their tentacles, percarbonate does penetrate though.
Yixing is somewhat porous, with tinny pores all over, the advantage of simmering in fresh water is that it helps to remove a greater amount of residue left over from the last user and or storage mildew. If the pot is not very dirty then this step might not be necessary. Prolonged exposure to high heat during simmering helps to unclog those small pores giving them a deep cleansing bath.