MY SHOP

Tuesday

“Superheated Tea” (the physicist’s answer to instant tea and tea bags?)

Before one reads further on please read this – don’t forget to come back here.

DISCLAIMER: I am not liable for any sort of damage that might occur as a result of anyone following this experiment or any other experiment suggested in here .

I did something stupid today (I tend to do stupid things but this was dangerously stupid and almost sent me and my friend to the hospital).

None the less, it was fun and I recommend you too do that - as long as you are absolutely safe.

So what did I do?

Well, I had what one might call a “superheated tea” or perhaps I should say “Instant Tea” (the teas were instantly ruined).

We tested various teas, Chinese green tea, Oolongs, Tenbu and even Tea bags using this water.

Whereas I recommend the experiment (it is very dangerous!), I do not recommend preparing your teas like this on a day to day basis if only because the tea taste …hmmm ‘different (?!)’. One can forget about any water pouring technique….
Needless to say there are no fish eyes and if you don’t watch it you will lose your own eyes.
In fact, this makes “old man’s water” look like it had a face lift.

Press here! for a short video of our first experiment– It contains some foul language and extreme violence so it is rated 18.

The teas were rather flat tasting, and for a reason (apart from the fact that some 90% of the tea leafs exploded anywhere but in the cup).

I suppose the reason is because one liter of superheated water heated to 101 °C (i.e. only one Celsius higher!) is already extremely unstable and can even produce about 3 liters of steam – instantly.

In English:
“The latent heat of vaporization of water is L = 2.23 MJ/kg. This means that it takes 2,230,000 Joules of heat to evaporate 1 kg of water at 100 °C and at normal atmospheric pressure. (One kilogram of water is about one liter.)
The specific heat capacity of water is c = 4.2 kJ/kg. This means that it takes 4,200 Joules of heat to raise the temperature of 1 kg of water by 1 °C.

Suppose that we heat one kilogram of water from 100 °C (its normal boiling temperature) to 101 °C, i.e. it is now superheated by 1 °C. When it begins to boil, it will very quickly cool to 100 °C, and the heat liberated turns water into steam. Cooling this kg of water by 1 °C gives 4.2 kJ, which is enough to evaporate c/L = 4200/2230000 kg of water.
This is only 1.9 millilitres of water, which does not sound very much, but it turns into 3 liters of steam. Those three liters of steam are created inside the hot water, quite suddenly, so the water is ejected violently from the container.”
(Source: http://www.phys.unsw.edu.au/~jw/superheating.html - Emphasis added)

I think it is useless for me to rewrite all the details so beautifully written by the “source”. Please have a look at it as it is very interesting and informative.

Furthermore, I realized that Diana Rosen from the Teamuse (a monthly newsletter by Adagio) conducted some similar tea experiments.
Her report is much more informative then mine. There is no need to repeat.

Note: If you have a proper functioning thermostat I would recommend that you superheat the water and test it after it cooled down to the usual temperatures. We can then compare notes.

Please don’t forget to report your results on here.

Yet again, this is a very dangerous experiment!
A F1 helmet is strongly advised.

Now, please don’t just read this.

6 comments:

Brent said...

Hmm... it might be the skeptic in me speaking, but when I see this I can't help but think "lawsuit waiting to happen." It just takes one idiot to do this wrong and work up the nerve to sue you.

While I agree that this is a fun experiment, from a purely legal standpoint you might want to put up a disclaimer saying "I'm not liable if you scald your face/hands/genitals so they are no longer identifiable as human" or something along those lines.

Sweet explosion, by the way. :)

Brent said...

Oh yeah... also be careful with the thermostat, as that can also trigger an explosion of the superheated water.

Ido said...

Hi Brent I have taken your advice on board, thank you :)

By the way are you going to try it? ;)

YEHEZKEL said...

Hey, i tried your experiment and the cup exploded in the microwave and harmed it badly..

I will send u a copy of the receipt for fixing the microwave and u will donate the amount of money mentioned to your favorit charity institute in your area,
bye the way i expect getting the Olive tree tea spoon as a condolence..

Brent said...

Haha, well, I was poking fun at the people who bring up ridiculous lawsuits, but it is an unfortunately legitimate concern over here in the States.

I haven't tried it yet, mostly because I'm clumsy, but it's only a matter of time before I feel bored and indifferent to bodily harm. :)

Anonymous said...

Thanks for posting this.. I guess superheated tea is a great idea, but a total disappointment not worth the risk :)

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