DaveC wrote:Actually that's true. Perhaps a machine with a small blasting cap on the coffee, electrically detonated when a button on the machine is pressed.

I reckon we would get it down to about 1s.....free plastic underpants supplied with each blasting cap conversion kit.

A button and electrically activated detonation sounds very civilised - technically we already have pump-action and lever-action espresso machines, so those terms are out

In Italian, Espresso means "expressly" as in "made to order expressly for the customer, not made ahead."

I don't think this is quite right, and I've just checked an online dictionary to confirm my Italian:

The Italian word espresso does mean "fast":

http://www.wordreference.com/iten/espresso

The English word "expressly" is apposta in Italian:

http://www.wordreference.com/enit/expressly

(I've confirmed these definitions in my paper edition of the authoritative Lo Zingarello Italian dictionary)

mathof wrote:I don't think this is quite right, and I've just checked an online dictionary to confirm my Italian:

The Italian word espresso does mean "fast" ...

The standard history texts may be wrong; but I have seen "piate espress" (excuse my faulty spelling) on hotel menus, for cold cut plates made after kitchen hours

Travisimo wrote:Others in the industry (LM & Illy) have been researching the benefits of higher espresso extraction processes. Although I found this hard to believe of higher pressures greater than 9 BAR benefiting espresso extraction esp with only 7gram shots! Yet I haven't been able to qualitatively try a taste of this Caffè Firenze of course!

I don't know about the compressed air stuff in the rest of the post. However, I can definitely confirm that at the beginning of extraction a higher pressure than 9 bar does yield good results. It's important to preinfuse for a while at 2 bar(perhaps 8-12 seconds) then the pressure must not be applied too quickly (otherwise machine can choke), up to 11 bar. Then of course how long you stay at 11 bar is up to personal taste. I normally only use the full 11 bar for around 5 seconds or so, dropping it progressively away to lower pressures as the extraction continues.

Comparing this with standard 9 bar profiles, or diminishing pressure profiles that max out at 9 bar...the results seem better in the cup with a little higher pressure earlier on.

To be sure 11 or 12 bar all the time will give a horrible result...the 9 bar must have just been the happy average manufacturers hit upon.

DaveC wrote:Pressure is VERY important to extraction, but how it's applied and how much is applied throughout the shot is what matters. 9 bar is just a happy average.

Nope. Pressure does not affect solubility / extraction. Not at all.

Pressure does not affect solubility / extraction. Not at all.

What does it affect then?

Flow rate potential.

mathof wrote:What does it affect then?

It was just a troll post, he introduced the word solubility himself. The Extraction being referred in the thread was the pulling of the shot (extraction). He introduced solubility, he then directly equated it with extraction, without actually clarifying anything....just looking to twist words around.

Flow rate potential.

His latest 3 word post reply is not clear....so, at the moment, I'm not sure what he is saying...I don't think he is either.

I expect that surrounding the coffee with compressed air prior to brew produces the "intense amount of super light and silky crema". Not surprising, since air will enter the grinds and then get released during brew.

Definitely not trolling. If the aim is the fastest extraction, the variables that you want to work are temperature, grind size, and agitation. Adjusting pressure does nothing to increase extraction, at least on it's own. You can optimize pressure for increased extraction over time the way espresso works, in that grind size is fine and agitation by way of flow rate is high. As it works out, 9bar in that method is historically the fastest extraction. However, as per JimS's suggestion, Turkish coffee is also very fast.