New Shigaraki teapot

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pantry
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Thu May 28, 2020 2:29 pm

Victoria wrote:
Wed May 27, 2020 5:11 pm
Baking soda on the other hand can be ingested and used as a baking ingredient. If you are concerned with abrasion soaking baking soda in simmering water with a protective cloth can help to dislodge old impacted organic materials. Just make sure to follow with a diluted vinegar wash to balance pH and remove all baking soda.

* partially quoting myself here from step D. in Cleaning: Awakening & Resetting Unglazed Ceramics / Yixing
I didn't know about the pH balancing step! I recently cleaned the inside of some of my pots with baking soda, and have found the resulting water made from these pots tasted a little off. I'm afraid of using vinegar though because of its strong smell. Do you think a drop of lime juice would work? Would the pH balance back on its own?
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Victoria
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Thu May 28, 2020 2:41 pm

pantry wrote:
Thu May 28, 2020 2:29 pm
Victoria wrote:
Wed May 27, 2020 5:11 pm
Baking soda on the other hand can be ingested and used as a baking ingredient. If you are concerned with abrasion soaking baking soda in simmering water with a protective cloth can help to dislodge old impacted organic materials. Just make sure to follow with a diluted vinegar wash to balance pH and remove all baking soda.

* partially quoting myself here from step D. in Cleaning: Awakening & Resetting Unglazed Ceramics / Yixing
I didn't know about the pH balancing step! I recently cleaned the inside of some of my pots with baking soda, and have found the resulting water made from these pots tasted a little off. I'm afraid of using vinegar though because of its strong smell. Do you think a drop of lime juice would work? Would the pH balance back on its own?
I use 1/3 white vinegar in filtered water, let it soak +-15min., and rinse. Vinegar odor fully evaporates within a day or two, so no need to worry. I prefer white vinegar, over lime or lemon which could lead to mold if any organic particles get lodged in a hidden crevice.
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pantry
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Thu May 28, 2020 2:51 pm

Victoria wrote:
Thu May 28, 2020 2:41 pm
I use 1/3 white vinegar in filtered water, let it soak +-15min., and rinse. Vinegar odor fully evaporates within a day or two, so no need to worry. I prefer white vinegar, over lime or lemon which could lead to mold if any organic particles get lodged in a hidden crevice.
Thanks for the tips! I never thought of that (organic particles)! I shall try with the so-so zini pot first and see how it goes. Thanks!
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Victoria
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Thu May 28, 2020 2:56 pm

pantry wrote:
Thu May 28, 2020 2:51 pm
Victoria wrote:
Thu May 28, 2020 2:41 pm
I use 1/3 white vinegar in filtered water, let it soak +-15min., and rinse. Vinegar odor fully evaporates within a day or two, so no need to worry. I prefer white vinegar, over lime or lemon which could lead to mold if any organic particles get lodged in a hidden crevice.
Thanks for the tips! I never thought of that (organic particles)! I shall try with the so-so zini pot first and see how it goes. Thanks!
Forgot to add, if you use very hot filtered water with 1/3 vinegar added, odor will dissipate/evaporate more quickly.
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Tor
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Fri May 29, 2020 4:16 am

pantry wrote:
Thu May 28, 2020 2:29 pm

I didn't know about the pH balancing step! I recently cleaned the inside of some of my pots with baking soda, and have found the resulting water made from these pots tasted a little off. I'm afraid of using vinegar though because of its strong smell. Do you think a drop of lime juice would work? Would the pH balance back on its own?
You can use citric acid, which is odorless.

I didn’t use acid after sodium percarbonate unless I wanted to also remove any lime scale. I just immersed the whole teapot in a large bowl of filtered water overnight, and never noticed any strange flavor.

My Shigaraki smelled like mozzarella cheese after its first sencha brewing. I simmered it in filtered tap water for an hour, changed the water, and repeated 4-5 times. After that the tea came out very nicely.

Some people don’t like to simmer their teapot and just rinse it with hot water. I’ve tried both ways with many new teapots and found that 9 times out of 10 I prefer to simmer it.
faj
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Fri May 29, 2020 6:14 pm

I left the pot with water in it last night too, and this morning tasted the water. I had a hint of a clay taste (nothing foul), no color I could discern. I will infuse tea with it tomorrow.

As an aside, I measured a quite significant drop in weight, happening over maybe 10 hours of drying. After rinsing with boiling water and waiting for water on the surface to evaporate until it seems dry, the teapot still holds about 4% of its weight in water. I never tested this with any other teapot, but I would think the amount would be negligible in most cases. This clay is quite spongy!

I noticed small droplets coming out on the outside every time the teapot had soaked in water and I then poured hot water in. It is water being pushed out due to pressure.

This teapot is quite interesting. One the one hand the clay is rough in appearance, but on the other hand the shape is very smooth and rounded. It fits wonderfully in the hand, the lid fit is flawless, and its tendency to drip from the lid and spout is minimal despite the clay being porous and rough. It seems so well made and balanced that it can afford the luxury of being almost too simple without becoming uninteresting. I hope I find good tea pairings for it, as this teapot is begging to be used.
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Victoria
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Fri May 29, 2020 6:47 pm

faj wrote:
Fri May 29, 2020 6:14 pm
This teapot is quite interesting. One the one hand the clay is rough in appearance, but on the other hand the shape is very smooth and rounded. It fits wonderfully in the hand, the lid fit is flawless, and its tendency to drip from the lid and spout is minimal despite the clay being porous and rough. It seems so well made and balanced that it can afford the luxury of being almost too simple without becoming uninteresting. I hope I find good tea pairings for it, as this teapot is begging to be used.
Beautifully expressed @faj. I also find Tachi Masaki’s sense of balance and proportion hits a harmonic note. Since it is porous it can make a tea that is a little thin slightly thicker. I pair mine, which I got from @Muadeeb (kyusu on the right side of 1st OP) with sencha and sometimes gyokuro. It’s size at 120ml and porosity works well with certain special Japanese teas. I could see getting a slightly larger one as well. What size is yours?
faj
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Fri May 29, 2020 7:52 pm

Victoria wrote:
Fri May 29, 2020 6:47 pm
I could see getting a slightly larger one as well. What size is yours?
120ml, like yours. I have purchased mostly teapots in the 100-120ml range to explore various clays with various teas. For preparing tea for myself, I like that size. I have a couple of bigger ones I have purchased from a fellow forum member which I use when making tea for two, but I see myself more actively seeking bigger bots if and when I find tea/clay combinations that my partner and I are likely to be enjoying on a regular basis.
leafandclay
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Fri Sep 30, 2022 6:49 pm

A while ago I was fortunate to acquire a kyusu by Masaki Tachi via Akira Hojo. I have been learning more about this master potter online, and came across this thread. Although I am late to the party, I must add some comments, because I am horrified by the ignorance displayed here, and disturbed the moderator did not review the advice given here.
Sodium percarbonate is far from 'nontoxic and environmentally safe'. It IS 'toxic to handle, irritable to skin and eyes and respiratory tract'. Even a quick search online will inform readers it is the active ingredient in detergents like OxyClean, and 'Ingestion should be avoided at all concentrations' ... and it absolutely should NOT be mixed with citric acid or vinegar, which also came up in some postings. Although sodium percarbonate is ~35% hyrogen peroxide, and hydrogen peroxide is used in, for example, dental care, that does NOT mean sodium percarbonate is safe to ingest at all. Sodium percarbonate is not only harmfully reactive with acids like citric and vinegar, it will also react with the natural minerals in the clay, especially the high level of iron compounds that give Shigaraki clay its distinctive red color.
Sodium percarbonate is also cumulative in the digestive system and will cause harmful internal problems.
The purpose of using red Shigaraki clay for a kyusu, like purion clay and some other rough or porous clays, is so the interior surface will absorb some of the tea prepared in it, and have a particular effect upon the flavor. The basic idea is that over time, this accumulated flavor will enhance further steepings. This is a desired effect. The clay, being porous, will of course 'seep' some of its color to the exterior, with some of the essences of the tea. This is a desired and anticipated effect, and the minute beads of tea essence should be rubbed into the exterior surface of the clay, to give it a patina.
To be blunt, all this brew-ha about how to eliminate normal signs of use tells us the owner of this pot does not understand the purpose of this kind of clay. Not to offend, but your question is like asking, how do I wear a pair of denim jeans and they will never get worn and faded, you see?
If you wish to counter the tea from steeping into the interior of the pot in the first place, soak the pot for a while in water before you steep tea. If the clay is saturated with water, it will absorb less tea. To clean a pot of porous clay, after your session simply rinse it after you remove the leaves, and fill it with hot water, and let it sit. Later, pour out the water, and let it dry with the lid off. Pots of porous clay should always be stored with the lid off so air can circulate. Remember, bacteria thrive in dark moist environments.
If any reader has followed some of the poor 'advice' given in this thread, do not despair that your kyusu is completely ruined. Follow the procedure just mentioned: immerse your pot in a bowl of warm pure water and let it sit all day and night, and pour it out, and do this daily for a week or so. Most of the harmful chemicals will leach out.
Thank you for listening, and I wish you good health!
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pedant
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Fri Sep 30, 2022 7:56 pm

hrm

welcome to the forum, lol ;)

i personally don't use percarbonate on teapots because it's never come up for me in any other project, and i'm satisfied with my existing cleaning methods/chemicals. i haven't bothered to buy some just for cleaning pots.

also, i honestly don't have a strong understanding of the chemistry of stain removal, and i have some doubts about it. for example, i've personally observed that bicarbonate appears to loosen stain. i'm talking about bicarbonate solution, not using it undissolved as a mild abrasive (which also works great!). what's the mechanism there? i know that tea stain has a large lipid component. or at least i think it does because, according to a paper i read, teapot patina has one. so is it saponification? i've seen grannies tout bleach (hypochlorite) as a quick fix to tea stains in their fine china, but how does that work? is it saponification, too? saponification would be a desirable mechanism in any case because it leads to solubilization and removal by rinsing with water. but what if it's degradation of a stain chromophore? this could possibly be the case for an oxidizer like hypochlorite or maybe percarbonate, so what if a lot of the stain is just rendered less colorful, and it's not actually being removed? i don't know if that's happening, but i wouldn't want that.
leafandclay wrote:
Fri Sep 30, 2022 6:49 pm
it will also react with the natural minerals in the clay, especially the high level of iron compounds
i too have wondered about potentially undesirable reactivity with exposed transition metals on the surface, but i don't know if that's actually happening. the reason i am concerned is that these non-vitrified metals at the surface may be at least partially responsible for the observed flavor reactivity with tea liquor, and i wouldn't want to mess that up. however, this is only a vague concern. i don't have any evidence one way or the other. you're presenting this with confidence, so how do you know this is really happening? do you have any literature to share in support of this theory?
leafandclay wrote:
Fri Sep 30, 2022 6:49 pm
Sodium percarbonate is far from 'nontoxic and environmentally safe'. It IS 'toxic to handle, irritable to skin and eyes and respiratory tract'. Even a quick search online will inform readers it is the active ingredient in detergents like OxyClean, and 'Ingestion should be avoided at all concentrations'
...
Sodium percarbonate is also cumulative in the digestive system and will cause harmful internal problems.
toxicity and environmental safety are all relative. sodium chloride is toxic and environmentally damaging. that said, percarbonate really isn't that bad. just try not to breathe it in, eat it, or get it in your eyes, and you should be fine. afaik, its reaction species are pretty short lived (and themselves benign in reasonable concentrations). the final, net products in normal, aqueous chemistry are water, oxygen, and carbonate.

besides, people rinse the teaware out pretty well after cleaning. they're not going to poison themselves. the clay won't hold onto it.
leafandclay wrote:
Fri Sep 30, 2022 6:49 pm
it absolutely should NOT be mixed with citric acid or vinegar, which also came up in some postings.
...
Sodium percarbonate is not only harmfully reactive with acids like citric and vinegar
why? which reaction species are you concerned about? i'm not seeing any problem, but maybe i'm missing something.
leafandclay wrote:
Fri Sep 30, 2022 6:49 pm
The purpose of using red Shigaraki clay for a kyusu, like purion clay and some other rough or porous clays, is so the interior surface will absorb some of the tea prepared in it, and have a particular effect upon the flavor. The basic idea is that over time, this accumulated flavor will enhance further steepings. This is a desired effect. The clay, being porous, will of course 'seep' some of its color to the exterior, with some of the essences of the tea. This is a desired and anticipated effect, and the minute beads of tea essence should be rubbed into the exterior surface of the clay, to give it a patina.
To be blunt, all this brew-ha about how to eliminate normal signs of use tells us the owner of this pot does not understand the purpose of this kind of clay. Not to offend, but your question is like asking, how do I wear a pair of denim jeans and they will never get worn and faded, you see?
this may surprise you, but many think that the benefit of teaware primarily comes from the material itself. these users contend that the buildup of interior patina actually decreases performance of the teaware over time because the material is no longer exposed to the tea liquor. they actually clean it to restore performance.
leafandclay
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Fri Sep 30, 2022 10:09 pm

Thank you for your swift and courteous response to my posting! It sounds as if you are somewhat versed in chemistry, so a point by point discussion is unnecessary and would no doubt become boring to other readers here, although I see this topic has not attracted much attention anyway.
I do stand by my concern. No sensible person would dissolve sodium percarbonate in a glass of water, especially with citric or another form of acid like vinegar, or add trace amounts of iron, and drink it for health, in any amount!
Although this was my first posting, I have been reading this forum for quite some time, and the general membership seems to be oriented toward high levels of purity in their teas, and with a refined sense of taste, and with how different clays affect the tastes of teas. Such an orientation is not consonant with the unnecessary use of the chemicals mentioned.
Granny is free to treat brown cracks in her fine porcelain as she wishes, and places like restaurants DO soak their coffee mugs etc in chlorine bleach in water, but that does not mean these are recommendable practices, or even that they are effective. The cosmetic effect of removing color is attained, but the substances that caused the stain are not necessarily destroyed or removed. The chlorine in urban tap water is considered 'safe', but chlorine is chlorine, something once used as a deadly weapon in warfare.
The term 'teaware' is too general for a response. Shigaraki red and purion clays have very different properties from glazed and porcelain wares. I think we are in agreement about my central point: it is natural and expected for wares of very porous clay to seep the tea within them, so there is no purpose in fighting this with chemicals. A simple rinse - scrub - soak with clean water should be sufficient. Thanks again!
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Fri Sep 30, 2022 10:24 pm

leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
I do stand by my concern. No sensible person would dissolve sodium percarbonate in a glass of water, especially with citric or another form of acid like vinegar, or add trace amounts of iron, and drink it for health, in any amount!
i agree, but i don't think anyone's doing that here (or recommending it). i believe they're removing it to the extent of zero concern or clinical significance. it's pretty soluble.
leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
The cosmetic effect of removing color is attained, but the substances that caused the stain are not necessarily destroyed or removed.
i share this theory, but like i said, i don't know if it's actually true! what if it does just harmlessly remove it?
leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
The term 'teaware' is too general for a response. Shigaraki red and purion clays have very different properties from glazed and porcelain wares. I think we are in agreement about my central point: it is natural and expected for wares of very porous clay to seep the tea within them, so there is no purpose in fighting this with chemicals. A simple rinse - scrub - soak with clean water should be sufficient. Thanks again!
i was intentionally general. i meant glazed and unglazed.

fwiw, i actually clean my teapots with bicarbonate paste and a cloth-covered finger. i just scrub patina/residue off. works for me.
i do this very infrequently for unglazed teaware though.

also, for glazed teaware, the abrasive action of damp cloth alone (without paste) often works for me. sometimes it takes some elbow grease.
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teatray
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Sat Oct 01, 2022 12:23 am

leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
Thank you for your swift and courteous response to my posting! It sounds as if you are somewhat versed in chemistry, so a point by point discussion is unnecessary and would no doubt become boring to other readers here, although I see this topic has not attracted much attention anyway.
As I use it myself, I would very much be interested in any point-by-point discussion of possible problems with sodium percarbonate, hopefully based on sources/well-explained deductions.

When you say:
Sodium percarbonate is far from 'nontoxic and environmentally safe'. It IS 'toxic to handle, irritable to skin and eyes and respiratory tract'.
It seems you are referring to Victoria's post from earlier in this thread:
Victoria wrote:
Wed May 27, 2020 5:11 pm
Even though sodium percarbonate by-products are non-toxic and environmentally safe, it is toxic to handle and can cause irritation to the skin, eyes, and respiratory tract, and when in contact with flammable materials enhances combustion.
Putting aside that "by-product" is not technically correct, the meaning is not lost. There is clear warning about toxicity and "non-toxic and environmentally safe" is not meant to qualify "sodium percarbonate" as your correction suggests.
leafandclay wrote:
Fri Sep 30, 2022 6:49 pm
Sodium percarbonate is also cumulative in the digestive system and will cause harmful internal problems.
This sounds scary and could be taken to mean that no matter how little you ingest, it all adds up somehow. That's not the case, see page 11 of this assessment report (OECD SIDS):
When sodium percarbonate comes into contact with body fluids it will dissociate into hydrogen peroxide, carbonate ions and sodium ions. All three substances are naturally present in the
human body. [check source for detailed discussion of each]
Searching for cumulative effects, this (NZ private sector) safety sheet comes up first, saying:
CHRONIC HEALTH EFFECTS
■ Prolonged or repeated skin contact may cause drying with cracking, irritation and possible dermatitis following.
Limited evidence suggests that repeated or long-term occupational exposure may produce cumulative health effects involving organs or biochemical
systems
Best to check any published studies, of course, as companies tend to minimize this stuff (the evidence might not be so 'limited'), but all seems to be in the context of harmful concentrations producing cumulative effects, not sodium percarbonate accumulating.
faj
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Sat Oct 01, 2022 6:11 am

leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
No sensible person would dissolve sodium percarbonate in a glass of water, especially with citric or another form of acid like vinegar, or add trace amounts of iron, and drink it for health, in any amount!
Percarbonate is a cleaning agent, not a powdered drink. I do not think it would be great to mix dish soap in a glass of water along with citric acid and drink that.

Saying something is not safe at high concentration and/or in large amounts does not imply it is unsafe at low levels of exposure. If you drink enough of it in one sitting, water will kill you because it will disturb your internal body chemistry.
leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
Such an orientation is not consonant with the unnecessary use of the chemicals mentioned.
You might also take it the other way : if people placing the purity of tea so high on their list of priorities use percarbonate, maybe it means it is not so bad after all.
leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
The cosmetic effect of removing color is attained, but the substances that caused the stain are not necessarily destroyed or removed.
Here is my take on that. I use glass items a lot when making tea. Glasses, teapots, pitchers. With time, especially with aged teas, there is a buildup that occurs. It has a color, sure, but it also has a thickness, a texture, you can scratch it. It can be scratched away with a fingernail. When cleaning glass with percarbonate, that buildup goes away, You can actually see small particles in the water. Once the cleaning is done, the surface becomes shiny and smooth, like new basically. I find it hard to believe that percarbonate would discolor the stain, polish it to a perfect, glass-like shine, make it hard and impervious to scratching, and make it undetectable to the naked eye where it was easy to notice before. I find it more credible that it actually removes the stain quite effectively.
leafandclay wrote:
Fri Sep 30, 2022 10:09 pm
The chlorine in urban tap water is considered 'safe', but chlorine is chlorine, something once used as a deadly weapon in warfare.
You seem to imply, without stating it, a conclusion about percarbonate that does not follow from the premises (which are that dissolved chlorine is considered safe enough to drink at low concentration, and can also be used to create chemical weapons). I think it would be more helpful to build an argument explaining why trace amounts of the byproducts of percarbonate mixed with water that may be left in a teapot after cleaning and rinsing could be harmful.

If your argument is that you are not sure it is safe, and not being sure you prefer not doing it, this is fine, but uncertainty as to the safety of a product is not proof that it is harmful.
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LeoFox
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Sat Oct 01, 2022 7:50 am

I wish peroxide persisted- to help with my stained teeth. My teeth has become pretty stained/ seasoned ( :lol: ?)over the years of tea drinking.
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