Newbie questions about yixing /zisha teapots AND source of good tea in Boston, MA area

Well again, I think you're correct about dashi, and I don't know about sushi rice, except to say that it would discolor the rice, for one, and sushi rice is served at room temperature which is not how you'd serve rice prepared with kombu. And your explanation of why it's left in the pot in macrobiotic preparation is probably right, except to say that pressure cooking is not new at all; traditional practice was to pile rocks on top of the pot. Pressure is a key element in traditional Japanese cooking. They even prepare "pressed salads" this way. What is less clear to me is the bitterness issue. I haven't experienced that when cooking rice with kombu. Traditional Japanese cooking is based on the 5-elements theory, which classifies rice -- all rice -- as being in the sweet category. Sea vegetables are bitter. The goal is balance. Maybe the reason my notes say to leave the kombu in is to balance the sweetness of the rice, and any strong bitter taste is then neutralized. I don't know. Anyway, when I think of really bitter sea veggies, I think of hijiki. And to prepare that you boil it for a long time to neutralize the bitterness.

Crymad makes a point about the "snotiness" if the komu is left in. Well, it does get slimy when pressure cooked, but that's the part that usually goes first when passed around at the table. Yum!

Bert

"Bert Fuller" wrote in news:bf8rbo$cg45g$ snipped-for-privacy@ID-184524.news.uni-berlin.de:

But sushi rice is always prepared with kombu.

The only thing that pressed salads and pressure cooking have in common are the letters "press" :-). Seriously, the techniques are entirely different. The pressure in pressure cooking comes from the steam inside the cooking vessel. The cooking vessel is completely sealed, so the gas pressure (water vapor and air, but mostly it's a water thing) goes up. This results in super-heated steam and shorter cooking times due to the higher temperature. (I also suspect that the higher pressure means the steam/cooking liquid permeates the food faster, but I can't point to anything authoratative that says that.) The key is that the cooking vessel is sealed. In a modern pressure cooker, that is accomplished with a rubber gasket and a top lid that interlocks with the base. The gasket provides the seal, the interlocking mechanism holds the top and bottom together so a seal can be formed, and also keeps the lid from popping off due to the difference between internal and external pressure. Without the gasket, there is no seal. Metal-metal contact would not be sufficient (unless, perhaps, there was some extremely expensive machining involved - not economically sensible today, easily damaged, and not available to pre-industrial societies). In a pressure cooker the pressure difference can be as much as 10-15 ppi. You'd need a *lot* of rock just to counter that pressure differential and keep the lid on, depending on the size of the pot.

In the west, the technique of putting things on top of a lidded cooking vessel used to be quite common. In particular, cooking coals and/or heated rocks use to be put on top of a dutch oven. (There's a similar French cooking vessel whose name escapes me whose lid even is indented on top in order to hold the coals/rocks.) The purpose of the excercise is to provide even heat, top and bottom. It's easy to see how that could be useful in preparing rice. I suspect this is the explanation for the traditional Japanese technique that you mention, not the development of steam pressure inside the pot.

OTOH, pressed salads made using weights (rocks, etc.) don't depend on vapor pressure being maintained or any increase of temperature over the ambiant. Totally a different thing, and definitely part of the Japanese cooking tradition. You can purchase pickling vessels in Japanese supermarkets in the US.

Strange. The hijiki recipes that I've used call for a good soak (20 min) in cold water, followed by quick cooking.

Did you learn Japanese cooking with a focus on a macrobiotic diet? That might explain some of the differences in what you are saying and what I know from my own experience and references. Macrobiotic cooking is definitely different in its goals, etc. than traditional Japanese cooking.

Debbie

"WNW" wrote

Brian Wright of Shan Shui Teas keeps a

I think I thanked you in another message, but I somehow broke the thread. Anyway, I have been looking up information on teas and am thrilled to know that there is such a depth to brewing tea.

I will definitely be learning to use a gaiwan as I look forward to trying various green teas. I have learned that I have been cooking my green tea leaves with overly hot water, I was wondering why I got the bitters and thought it was just poor tea! The gaiwan teacup seems a very sensible idea. I had seen them in the past in the basement of the antique store I work for (the gaiwans are probably not antique, but modern "riceware") but I had no clue what they were, all these little dishes! The owner of the store didn't know, either. I will educate him. : -)

I have 2 small (one 7 oz and one 8 oz) YiXing pots on order, inexpensive ones as don't want to break them and my bank! I will use one for pu-erh tea and one for oolongs, both for personal consumption.

For the tea I brew for kombucha(not-seaweed-tea-but-cultured-like-vinegar-fizzy-like-beer-health-drink), since the final taste is altered and served cold I will stick with my pyrex glass bowl as a "teapot" as I brew 2 quarts at a time.

I have had fun reading up on brewing teas at the various websites I visited. My favorite sites so far are

and Both have useful information that was interesting.

Thanks again, I think I have formed a new hobby, and can't wait to try the teas I have on order!

Regards,

Heather

Thank you very much for the tip, Debbie, I have joined the group, I think it will be a useful resource for me.

Best,

Heather

Minor correction to my previous post. The unit for pressure should have been "psi" (pounds per square inch), not ppi. The math was correct, however.

Of course the newer cookers would enable more pressure and cook faster; who would argue with that? The "older-modern" pressure cookers used to cook rice at about 5 psi. Let's cut that in half for ancient attempts. That would certainly not require anywhere near 380 lbs of rocks. The newer models typically use 15 psi. Now having said that, it occurs to me we may have a definitional problem here. Apparently to you, pressure cooking requires a gasket and a valve or it's not pressure cooking. I'm using the term in a much broader sense to include weight as a way to limit the escape of steam from the pot. In outdoor Dutch oven cooking, you typically place hot coals on top of the very heavy cast iron lid. It isn't merely the additional heat that speeds the cooking, but the weight. Now why don't you do an even simpler little experiment: Start some water boiling in a covered saucepan. As you hear the molecules agitating, press down on the top of the pot. You will hear the boiling process speeding up, and you won't even have to push hard. You don't want to call this pressure cooking? Fine, but in a broader, more inclusive sense, I do.

Bert

"Bert Fuller" wrote in news:bfc49f$d1mcj$ snipped-for-privacy@ID-184524.news.uni-berlin.de:

Nope. Sorry. No seal, no pressure differential between the inside of the pot and the outside of the pot. No pressure increase in the pot, the steam stays at the same temperature (local boiling point) and the cooking proceeds at the same rate. Any noticible gap means the steam will escape. Smaller gaps (due to pressing down on the lid, or effectively increasing its mass by putting rocks on it) just means the steam will move faster as it goes through. As long as there is a way for the gas to escape, it will. That's what is happening in your experiment. When you reduce the size of the gaps between the lid and the pot, the escaping gas simply moves faster through the remaining gap area. Thermodynamics tells us that the pressure on both sides (inside of the pot and outside of the pot) will be equal if there is a way for the steam to escape. There is no steady-state increase in the steam pressure. You can press down as hard as you like on any pot and lid, but if there is not a seal, the steam will escape, and the steam pressure will be the same inside the pot as outside. The bottom line is that weight on the lid (or a heavy lid) does NOT stop or limit the escape of steam through the irregularities between the lid and the pot.*

Without a pressure differential, the cooking inside the pot will take place at the boiling point of water. That is not pressure cooking. Pressure cooking is all about cooking with moist heat (steam) at a temperature above the boiling point of water by means of an airtight container. That's what my dictionary (Webster's New World) and cooking references (many) say.

If there is any advantage to cooking with rocks on top of a pot lid, then it has got to be thermal mass. If the rocks are heated in advance, as coals are in old-style hearth cooking using dutch ovens, the food is heated from above and below, resulting in more even heat and faster initial heating due to two heat sources. (Note, however, that the steam/water in the pot does not exceed the boiling point.) Even if the rocks are not heated in advance, over the course of cooking they will heat up and the temperature in the pot will be more even top-to-bottom.

Saying that putting weights on top of a pot lid (essentially increasing the mass of the lid) is the same as increasing the steam pressure inside a pot (elevated steam pressure inside a sealed vessel) is at best a confusion of cause and effect, and in this case, there isn't even a cause and effect relationship, because no matter how heavy the lid is, there is no seal between the lid and the pot and without a seal the water and steam in the pot will not go above the boiling point. The same thing goes for your earlier comment about brakes. There the heat is generated due to friction. If the parts of a braking system were perfectly smooth, no heat would be generated regardless of how much pressure were used to keep them together. Saying that you are trying to be inclusive and there is relationship between two different cooking techniques because somehow you've used the word "pressure" to describe both makes no sense if they are completely disjoint, which they are. It is inclusive to say that both men and women are humans, but it is meaningless to say that any two humans can get together and make a baby. One can be philosophical and qualitative, and there are times when that is the most useful thing. However philosophy does not substitute for science. Or vice versa, for that matter.

Debbie

*Getting philosophical, I suppose one could imagine applying sufficient pressure to the area of the pot lid directly above the pot to close the gaps between the two. Of course the amount of pressure required to deform the metal this way would be far in excess of anything practical in a kitchen - hundreds of pounds wouldn't even begin to do the trick. This is why pressure cookers use a rubber (or similar soft material) gasket. It's much easier to deform sufficiently to form a seal.

Not that this keeps all manner of strange and unnatural combinations from trying...

--crymad

crymad wrote in news: snipped-for-privacy@xprt.net:

Hehe. Though the people involved may not feel that what they are doing is in any way strange or unnatural! And their goal may not be making babies, either.... which indeed is often the case anyway.

Debbie

"Bert Fuller" wrote in news:bfemv3$dtjan$ snipped-for-privacy@ID-184524.news.uni-berlin.de:

Tea hee. (on-topic pun intended)

Putting weights on a salad doesn't make it get any warmer, let alone warmer, faster. Neither will putting rocks on top of a covered pot. In fact, putting rocks on top of a covered pot exerts no pressure on the food being cooked inside the pot, assuming the lid is resting on the rim of the pot. I suppose that if you put the rocks directly on the food, that would be another thing... but unless the rocks were hot when you put them on the food it wouldn't speed up the cooking in that case either.

Science and scientific definitions are very useful when you want to solve a problem or get things done. A proper science-based definition of pressure cooking will help solve the problem of cooking things faster using moist heat. A supposedly general definition (which as noted above doesn't apply in any way to the scenario at hand and ignores the common usage, to boot) is at best of little use in solving that problem; at worst it can cause confusion and failed attempts at cooking.

Bert, I have been persuing this topic with you because there are people out there who have little background, bent, or interest in science, but are interested in cooking. When someone makes a strong assertion, they have no way to know if it is correct or not. I don't want them to think that they can pull out a recipe that calls for using a pressure cooker, substitute a pot, a lid, and some rocks, and expect their meal to turn out as expected in the time the recipe gives. They are counting on and trusting in science, and should have a fair chance to benefit by it.

Debbie

snipped-for-privacy@ix.netcom.com (Space Cowboy) wrote in news: snipped-for-privacy@posting.google.com:

Thanks, Jim. You know, physics was my worst subject in college. Newtonian mechanics was okay, even though they were using partial differentials in a first-semester freshman course (this was a hard core science/engineering school), but e&m really threw me that spring. Shroedinger's equations ground me to a dead halt. Thank goodness freshman year was pass-fail. The next year I had to take thermodynamics. The particular course had a deadly reputation on campus. (There were easier versions of thermo available for those whose majors permitted.) However I was pleasantly surprised to be on course for an "A" until the final. Argh. These memories are 30 years old! But it is funny how old coursework sometimes does apply to real life, and how it comes back to one when the subject arises.

Pressure cookers are great for beans, too. I love chickpeas, and the pressure cooker makes fast work of them. However my current favorite use for my pressure cooker is making broth. It is so much faster and you get all the gelatin out of the bones and cartilege. Yummmmmm.

Debbie

Cook the carcass under pressure the fat will rise to the top followed by gelatin let sit overnight in fridge chip away the fat spoon away the gelatin. The meat falls off the bone. I grew up in a time where eating beans meant you were poor and I ate my share not realizing that today I would be a poster child for a food group. So I'm the guy at Black-Eye Pea who crumbles his corn bread into red beans and rice and empties the tobasco bottle. You can add another 10 years since my last diff-e-q class.

Jim