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Critical Point Espresso

 Very strong coffee
  (+3, -2)
(+3, -2) 		  [vote for,
against]

Espresso is strong coffee made by forcing superheated high-pressure water through coffee grounds. The high temperature and high pressure make it taste good, but I think it could be better.

Why not heat and pressurize the water as much as physically possible? In the critical point espresso machine, coffee is brewed at 647.096 K and 22.064 MPa, resulting in a very strong cup of joe.

—AO, Mar 26 2003

Best brewing temp: 195° - 205°F http://www.redbagco...tion.com/roast.html
26 Mar 03 | Several sources all say the range is right around 200°F. [bristolz, Oct 04 2004, last modified Oct 06 2004]

Datasheet for caffeine http://www.sciences...com/msds/C1410.html
Y'all be careful with those beans, now. [Basepair, Jul 29 2005]

[link]






       Croissant just for using water's critical point in a HB idea. Enjoy it with your coffee, but don't burn your mouth on the steam.
—Worldgineer, Mar 26 2003
   

       Would you need some sort of special shatterproof vessel to hold it? I imagine a porcelain cup more or less exploding on contact.
—snarfyguy, Mar 26 2003
   

       You'd have cool it down then depressurize it before you release it, otherwise it's flavorless steam. If you do that, your porcelain cup would hold it just fine.
—Worldgineer, Mar 26 2003
   

       I thought that coffee brewed to it's best flavor at ~190°F or so. Is what's being forced through the grounds in an espresso machine steam or water under pressure?
—bristolz, Mar 26 2003
   

       Okay. Would very high temperatures affect the physiological effects of the alkaloid compounds?
—bristolz, Mar 26 2003
   

       I would image that at that high of temperature and pressure, strange things would happen chemically. I would imagine coffee grounds would reach their more stable state - that of burned coffee. Of course I don't know this and am waiting for AO's prototype.
—Worldgineer, Mar 26 2003
   

       [bristolz] As I recall, from my coffee-flogging days, the darker roasts all had comparatively lower caffeine contents. I was told that this was due to higher roasting temperatures/duration. Not sure how this applies when water is involved, however.
—brenna, Mar 26 2003
   

       Would you force the entire bean into solution?
—bungston, Mar 26 2003
   

       The coffee version of crack!
—snarfyguy, Mar 26 2003
   

       I too have read that the light roasts have more caffeine.
—bristolz, Mar 26 2003
   

       Keep it down in here guys, you woke bliss up.
—Worldgineer, Mar 26 2003
   

       Are you assuming I'm human, and not the new line of human-emulating web-bot?
—Worldgineer, Mar 26 2003
   

       Since espresso exists purely to be cool and trendy rather than to taste nice, I think this idea must be applauded as its logical conclusion. And if a few trendoids were to accidentally suffer horrendous internal scalding, that would simply make it even more chic and exciting.   

       (Incidentally, am I the only person who (while a child) assumed that when a book spoke of a mother scolding her son, it meant she dumped the infant in a pan of boiling water as a punishment.)
—pottedstu, Mar 27 2003
   

       Coffee = liquid nastiness
Extra strong coffee = liquid evil
—-alx, Mar 27 2003
   

       I would go for this, as long as there was a decaf version.
—sild, Mar 27 2003
   

       From the annotations it sounds like this machine might produce something almost, but not quite, entirely unlike coffee. It's worth a try, though. You'll never know what you might discover.   

       "Try to understand. This is a high voltage coffee containment system. Simply turning it off would be like dropping a bomb on the city."
—st3f, Mar 27 2003
   

       Having experimented a bit with my espresso machine, it seems that the finer you grind the coffee and the harder you pack it down into the filter thing, the stronger and tastier the coffee. I reckon if you ground the coffee really superfine and packed it with a half ton weight, then forced the water through at mega pressure (not mega temperature that would ruin the taste) voila. - a tasty brew from Coffee Concrete.
—Lunartick, Mar 27 2003
   

       Further to my coffee crack anno:   

       Can coffee beans be ground and smoked? Would they burn? Or would you need to combine them with some kind of chemical to enhance ignition, or maybe create some kind of bonded chemical coffee substance that, when held over flame, doesn't burn but rather emits the essence of the bean?   

       Pass the pipe.
—snarfyguy, Mar 27 2003
   

       I'm with Bristolz's link. there has been a fair amount of baking on this and the just below boiling seems to be well established. You can test this yourself by using a pressure cooker I suppose. My over cooked coffee accidents have always been "over extracted" and boiled off the tasty oils. If the caffeine survived I suppose it was all out of the beans. But if that is what you want you should look in to freebasing Jolt by cooking it down.   

       No croissant for you! We must rush you to the burn clinic instead.
—DadManWalking, Dec 20 2003
   

       Baked by McDonald's, who decided that it was a good idea to give coffee to people at inanely high temperatures. Result: burned crotch, big lawsuit.   

       Fishbone!
—disbomber, Apr 04 2005
   

       I like the idea, a pressure cooker may be just the thing.   

       Where I live, we have a mountain call Pike's Peak. It is 14,110 FT (4,300 M). There is a roadway to the top and after my car has struggled and wheezed it's way up, I've often wondered how to make a good cup of espresso at 87 kPa.
—dougp01, Jul 29 2005
   

       I'm not at all optimistic about caffeine surviving at over 300°C, let alone the flavour compounds.

Pure caffeine is pretty cheap, and can be added cautiously to a regular espresso. The results can be jolly surprising (never again).

Incidentally, in searching for data on the thermal stability of caffeine, I found this (linky).
—Basepair, Jul 29 2005
   

       The oils in the beans would not be able to withstand such heat. If there was a way to generate that amount of pressure without the high heat, it might work. Also keep in mind that the longer the water is in contact with the grounds, the more extraction of bitterness will occur. Hard, fast and just below boiling temp - get those in combination with the right grind and you'd have something!
—CoffeeWoman, May 01 2007
   

       Hold on. Hold on hold on. There must be some point at which the relevant coffee compounds become tolerably soluble in water. Once you've reached that point, it is merely a matter of letting things reach equilibirum. The best you can ever do would be to have the compounds uniformly distributed between the grounds and the water. Beyond this, you achieve nothing except pyrotechnics.   

       I suspect that the reason espresso is so fuckably good is just that the ratio of water to grounds is very low. The high pressure then serves simply to squeeze this small, enriched volume of water out of the grounds.
—MaxwellBuchanan, May 01 2007
   
      
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