Brewing Properties: Porcelain vs. Zisha

Very interesting. Excuse my ignorance but what is "yan"?

Temperature could be a dominant variable here. If all things are equal, particularly steep times, have you measured the temperature after the steep time was up? It would be interesting to see if there was a detectable difference.

You tried compensating the porcelain to make up for your perceived difference, have you tried mimicking the porcelain results by compensating the Yixing pot?

Is the porcelain vessel a gaiwan or a similarly sized teapot? I am finding myself wanting to go out and get gaiwan now! It might be interesting to see 2 different faces of the same tea!

Mike Petro snipped-for-privacy@pu-erh.net

Cameron,

Interesting observation. I have not been brewing my oolongs in porcelain lately; I have been using exclusively yixingware, and the lack of sweetness I've noticed is something I've been ascribing to my current batches of these teas. In fact, I've been changing temp and time parameters to try to bring out different taste elements.

You've encouraged me to experiment with porcelain.

I'm interested in your interpretation of "yan" as well.

Joe Kubera

Cameron snipped-for-privacy@posting.google.com7/6/04

It's a very worthwhile experiment, to be sure. YiXing clay pots of different qualities are recommended for different teas -- wall thickness, porosity, size. Wuyi wants a very thin wall, while Pu-erh wants a thicker more porous walled larger pot. Based on your comments, Cameron, I'm going to try preparing some Wuyi teas in a porcelain lidded cup to compare.

Meanwhile, have you used your clay pots a lot? Have you dedicated each one to one type of tea, or are they generalists? I'm just wondering if this might be a line of enquiry, realizing that a well used clay pot used for one tea only ought to refine the taste. Who knows. Thanks for opening up the question.

Michael

It's nothing new to me that the same tea taste different enough in teapots of different materials. In my case, blacks in stainless steel, oolongs in porcelain, and greens in clay. There are other factors such as size, glaze, eddie viscosity. I don't like the taste of any new teapot till it develops a patina. That even includes stainless steel. I always boil water and find porcelain pots cooler than clay. If someone wants to make a case that glass is the best material for making tea because the leaves brew better exposed to light who can argue? You'll need a glass pot to understand eddie viscosity. I think what makes the Brown Betty (bowed body) such a great teapot is the 'big splash'. The leaves are thrown up on the sides and tumbled with the infusion like a front loading washer.

Jim

Space snipped-for-privacy@posting.google.com7/7/04

Jim,

Who's eddie? Or perhaps I should ask, What's eddie? Eddie viscosity?

Michael

Literally, rock or cliff, referring to the crags in the Wuyi mountains of northern Fujian where much-loved oolongs originate. It's a word that connotes the qualities of high-grown Da Hong Pao, Bai Ji Guan, etc., and it's open to interpretation, to say the least.

/Lew

I haven't noticed it, but that's because I use the same little glazed pot for everything that a purist would brew gongfu (no room for lots of kit in our tiny apartment.)

But I'm puzzled by one thing: you seem to be ignoring the possibility that the difference you've noticed is because of the fact that zisha interacts chemically with the liquor, while vitreous porcelain is (I

/Lew

Lewis snipped-for-privacy@panix1.panix.com7/7/04 11: snipped-for-privacy@panix.com

We could be talking that flinty resin beneath the other neat fruit floral tastes moving mysteriously through your mouth. Now about that red robed rooster crossing the road, anybody see my turtle?

Michael

To get to the other side, silly!

/Lew

Yan is a complex set of tastes the Chinese ascribe to certain teas. Yan is the unique flavour found in the "rock" teas of WuYi (yancha) and tastes very much like limestone smells, though I tend to include certain sorts of woodiness, steely and mineral tastes as yan also (which may or may not be correct).

I've used both a gaiwan and a porcelain teapot of similar size and fairly similar shape to my yixing pots. Since the volumes of the vessels involved differ slightly I simply maintained the tea:water ratio. In all cases the porcelain brewed teas were similar as were the effects of the yixing. So far, the teas I've tested have been various green puers, tiguanyins, dancongs, a wulong, and a yancha from WuYi.

When you said I should try compensating the yixing pot did you mean I should try and increase its cooling rate? I suppose that some cool water poured over the pot should do the trick.

I think I'm going to have to arrange a double-blind test for this.

Cameron

My pots are all dedicated to fairly specific categories (green puer, green tiguanyin/dong-ting, dancong) and with the exception of a new pot for wulong/darker tiguanyin have been in use for months to years.

I'm quite careful to avoid unfortunate crossovers. In fact, I first noticed the porcelain-zisha difference because I test new teas in porcelain for compatibility before risking their use in a zisha pot; a habit I picked up from pipe-smoking (corn cob before briar).

Cameron

Interesting discussion - thanks for starting it!

IMO, temperature and carryover effects are very likely the only major factors. Simple pronouncements about thermal properties of various materials are mostly wrong, as they fail to deconvolute heat capacity, thermal conductivity, internal convection (is that what "eddie" means?) and evaporation, direct or via transpiration. Without getting into all that, the easiest way to control this is to preheat carefully, time carefull, control swirl (a lot in a big pot, or none at all in tightly packed gong-fu) and, mainly, do everything in a big water bath almost as deep as the pots. This will nicely normalize all the temperatures.

I flatly don't believe in oxygen effects, not having seen even a speck of credible data (which would be easy enough to generate) in several decades. But there's no doubt that unglazed pottery is more porpous than glazed porcelain. Neither is "inert" in the usual sense of the word, but both probably passivate very quickly - note how few brews are needed to remove the taste from even the rawest clay pot. (Steel is different. I can't imagine making tea at home in stainless, but chacun a son whatever. I use stainless screens, but keep them carefully crusted up with no metal showing.) Anyway, even glazed porcelain has some porosity, but thousands of times less occluded volume than Yixing ware. Not only can stuff carry over between brews, but residues in those little holes can react slowly with air and other things, absorb odors from the air, and otherwise store a lot of unintended flavor. Adsorption (note the d vs. b) onto clean clay surfaces is a dramatic, so a room with a little garlic, onions, fresh paint, soap, or anything else smelly is likely to load tens of micrograms (i.e., a lot) of smelly stuff into the pot to be released at varying rates into the tea.

-DM

Dog Ma 1aP0Hc.211590$ snipped-for-privacy@bgtnsc04-news.ops.worldnet.att.net7/7/04

snip

That's it! I give up. So maybe *that* was Luk Yu's secret recipe?

Oops my misspelling. It s/b eddy. It's the scientific name I give to the 'agony of the leaves'. There is an eddy from heat convection of the water causing a viscosity at the surface of the leaves for leaching. Different tea pot materials cause different eddies which changes the viscosity at the surface of the leaves. If you had xray vision the agony of particular leaves in a clay teapot would be different than porcelain. I used a glass pot for so many years I could tell ideal brewing time just from the visual clues of the leaves in the infusion for any given favorite tea. The other thing I like about glass it adds nothing to the taste which makes it an excellent reference standard for comparing tea taste to other pots. My love affair with glass pots came to an end when one shattered in my hand. I broke other tea pot materials but you're not going to cut yourself. The other day I put a lawn mower pebble through the exterior pane of a double glass patio door slider. It started from the chip break and continuously fractured for a couple of hours till the pane fell out.

Jim

It's supposed to do that. Tempered glass breaks into little pieces instead of dangerous big ones. Too expensive for teapots, alas, and there are some engineering diffculties.

It's easy enough to make chemically tempered glassware, though. Lightbulbs treated this way don't break when dropped on a hard floor - quite amazing. Wonder if there's enough market to make the product?

-DM

Dog Ma 1xtiHc.216890$ snipped-for-privacy@bgtnsc04-news.ops.worldnet.att.net7/8/04

I can empathize with that pane of patio door. Sounds like my life sometimes: Slow, but inexorable and irreversable shattering.

Thought they imploded like TV picture tubes. Do they still have TV picture tubes?

Drinking Rou Gui Wuyi Oolong, a yummy and joyful tea, but ya gotta use lots of leaf and really hot water, and a minute or so of steep. Got this one from TeaSpring. I understand that of all their Wuyi Oolongs, this is the only one from young trees, but still excellent balance with just hints of fruit and flower showing through the warm rich round and friendly light wood and custard of it, true and balanced from aroma to aftertaste.

Listening to Bob Marley Jamming. Joyful as the tea. A perfect mating.

Michael

The window replacement shops have thicker thumb and forefinger calluses than my local tea shoppe owner. The total glass pot is almost a dinosaur. If I use glass it is a French press with plastic cradle.

Jim

You need to listen to classic country music. One time a Jamaican offered me some ganja and I thought he was talking about gong cha. I wasn't disappointed.

Jim

Space snipped-for-privacy@posting.google.com7/9/04

Ganja? What's ganja? Don't answer, just joking. Ever hear of Bang? Obviously not, you're still walkin' and talkin'. So, what classic country do you recommend?

Once upon a time in Quetta...but that's a story for another day.

Michael Drinking Bai Mudan and listening to Lonnie Johnson this fine morning.