need help cleaning my new airpot

Citric acid is actually especially good for chelating (binding and solubilizing) water scale, better than vinegar. TSP (trisodium phosphate) is much better still, and readily available at hardware stores. Wash it out throughly afterward - it's not particularly toxic or anything, but you might not like the taste! And keep out of eyes: it's strongly alkaline.

In case this is useful to anyone... Removing tea stains from porcelain with warm, dilute chlorine bleach is optimal. There's some specific chemistry that makes this especially effective on tannin films. If you worry about residues, just brew a little weak tea in the pot afterward, and the same reaction will turn any residual bleach into salt. (Tea is likewise good for removing excess iodine taste from purified camping water.)

If you want to use TSP on porcelain or glass, though - don't! It's such a good chelator that it actually etches glass and ceramics. Instead, use concentrated dishwasher detergent. It contains the same kind of goodies, but also powdered silica just to counter that reaction. I occasionally remove scale films from abused antique glassware by simmering for an hour in a potful of water with half a cup of dishwasher powder, and it works pretty well.

BTW, toothpaste is a dandy cleaner for valuable ceramics, since the abrasive in it is, by design, softer than most ceramics. But the flavor may be hard to remove from a porous pot, so I'd be careful on that front. At least start by thoroughly water-soaking the pot so that less goop is absorbed. I just scrub new pots with a rough sponge (no soap), simmer them in cheap green tea for an hour or so, and wash in plain water. That tends to remove any clay taste and other things I don't want to know about, and leaves them ready to season.

-DM

Any citrus juice (lemon, especially.)

That's acetic acid, different chemical.

Ok, I'm a little confused. I could be wrong, but aren't tannins acidic? I know bleach certainly is. So when an acid and an acid react, a precipitate, especially a salt, usually doesn't form. You get that sort of end product from an acid-base reaction, right?

Damn. Isn't it great to have a real scientist here to explain this stuff? I didn't know most of that.

Thanks, DM.

Joe

Nerdy post alert...

KeemunBLK wrote:

"Acid" means several things to a chemist, who will understand the relevant usage from context. Lay-people may be misled. Inorganic acids like sulfuric and nitric are highly ionized in water, in some cases dissolve metals or fingers, etc. With a few exceptions, organic acids are only slightly ionized in water, and not strongly corrosive. They are still technically (Bronsted-Lowry) acids because they have a proton more readily solvated than those on water. Common examples are citric and ascorbic in fruit, oxalic in spinach, acetic in vinegar. The first three also happen to be good "chelating agents" - they have extra dangly bits that help bind metal salts, so they remove lime scale better than other weak acids.

Tannins are "acids" because they have a slightly ionizable phenolic proton. But they aren't really acidic in the everyday sense; just enough to be a little extra soluble in water that is alkaline. When ionized, they are also more easily oxidized into things that are very soluble in water. So alkaline oxidants like laundry bleach are great for removing tea stains. And tea is great for neutralizing excess bleach in a teapot.

Perhaps there's a bit of confusion between removing lime scale from kettles and removing tea stains from cups; apologies if I've added to it.

-DM

This is interesting, but I still find myself reluctant to drink bleach.

/Lew

Bleach is a base. I know this could've been inferred from Dog Ma's excellent post, but I thought I'd chime in.

Drinking some Harmutty Assam that was on sale a few weeks ago at Specialteas. Mmmm.....Love Assams....

Melinda

Understandable. I wouldn't drink bleach, but often use it to remove tea stains from porcelain. AFAIK, ordinary "chlorine" and persulfate bleaches have nothing toxic in 'em except their oxidizing ability. Once this has been neutralized with a little tea, all that's left is harmless salts. But NEVER try mixing bleach and ammonia!

-DM

This AM, served a Keemun Hao Ya A - kindly provided by Mr. Plant - to people who had never before taken black tea w/o milk, and who loved it. This PM, made three pots of a pretty good conventional Keemun, drab by comparison. Why do people insist on encouraging me in tastes I can't afford?

For tea stain removal, I use baking soda, which seems more ... forgiving?

/Lew

:O)

I just now poured the first cup of a difficult choice. I decided to save the last little bit of Hao Ya A, and instead brewed a different Keemun.

Still, very nice. Has a cocoa-biscuity (I think that's what's meant by 'biscuity') kind of thing. It doesn't rival the Hao Ya A, though.

:/ Oops, I thought bleach was primarily hydrochloric acid.