Te' Tees: Royal Keemun Mao Feng Supreme

And I'll tell you something interesting.

If you put your nose in the tin, you get a nondescript herbal scent. Nothing like the smoky sweetness that comes out of the cup.

--Blair "I'll have to remember to forget to worry about it."

Today I came back to this tea. I got two solid infusions and one that was probably 80% strength. In 10 oz batches.

Which cuts the price/cup down to 6-9 cents/floz, if you don't mind that third cup being a little weak (and I don't; by then it mostly sits until it cools anyway).

Here's some more info:

There's a faint mark on the inside that says "minimum". I've been filling it a bit short of that. The mark is at 410 ml (I measured it by weighing on a digital scale).

500 ml is conveniently at a very identifiable spot where the top of the heater-mount molding joins with the inside of the pitcher.

I've also been taking some data.

Mass: 410 g H2O

time temp temp Delta Delta Delta Power (s) (C) (K) time(s) temp(K) energy(J) (W)

0 29 302 15 29 302 15 0 0 0 30 35 308 15 6 10292.64 686.18 45 46 319 15 11 18869.84 1257.99 ** 60 54 327 15 8 13723.52 914.90 75 64 337 15 10 17154.40 1143.63 90 73 346 15 9 15438.96 1029.26 105 80 353 15 7 12008.08 800.54 120 88 361 15 8 13723.52 914.90 135 94 367 15 6 10292.64 686.18 150 97 370 15 3 5146.32 343.09 Boiling 165 99 372 15 2 3430.88 228.73

Total energy 116649.92 777.67 Average power

Mid-curve energy gain: 111503.6 (from 15 to 135 seconds)

Nominal power at mid curve: 930 Watts

Altitude: 1150 ft above sea level

** lag in measurement due to lack of convection; I didn't stir this; once the heat builds up it begins convecting itself; the boiling happens well below 100C measurement because (1) this isn't sea level and (2) the probe is still delayed a bit compared to the heating element; while the absolute times are off because of these delays, the differentials average out

When the water starts to boil, the energy goes to creating steam and the water stops getting warmer.

--Blair "Science is fun."

Pretty interesting. I remember hearing about chinese bubble-counting techniques. Given a constant or known heat flux, one can count the rate of bubble formation to determine the temperature. It is interesting, usually when something starts to boil, the heat transfer rate starts to go up due to the mass transport of steam bubbles into the cooler bulk. That effect would probably be hard to measure.

Steve

You get an inversion layer (hot water at the bottom, cooler above) and convective flow as soon as the element starts to heat.

Bubble counting might be a reasonably calibrated temperature guide, but only for a given vessel. The availability of cavitation sites makes a huge difference and they are, of course, random.

I've been boiling water in clean smooth vessels in the microwave at work a lot, lately*, and it's kind of fun seeing the bubbles appearing right in the middle of the cup. The water must be superheating in there. This is the sort of water that bubbles up dramatically when you add anything to it like a spoon or a teabag. I give it 10 seconds or so to equilibrate after I remove it now, because I don't know what tea might do if it hits a pocket of 230-degree water.

• - interesting tip: this nuker is clearly designed so that the turntable returns the food to the front exactly every

10 seconds, probably on the presumption that almost all cooking times will be a multiple of 10 seconds; clever bastards. But now I'd rather heat the water an extra 5 seconds than save that 5 seconds and have to reach to the back (it's a *big* nuker).

--Blair "The next 200 years of tea had better be more interesting."