Pressure and other important things...including some websites.June 17 2002 at 1:38 AM
|Peter Chong (no login)|
Response to The Answer As Explained to me by an old italian
Thanks Jeff for your info.
I understand from the big gurus of coffee, that to brew good espresso with a good thick crema, and aromatic coffee...three critical factors are indicated:
1. Pressure of the machine.
2. cleaniness of the machine.
3. grind of the coffee.
The pressure required to produce a nice crema is 9 bar. Most home pump machines (not to be confused with consumer variety which are not pump operated) will generate 15/16 bar. My tiny Seaco Magic does.
Cleaniness is the most important, once one has paid for a good machine. That's why many cafes do not serve good coffee, even if they use those big buck, very good commercial machines. That's also why, in a cafe that does serve wonderful coffee, the barista is always cleaning his equipment in every single free moment he has.
And finally, the grind. A good grind, well tamped, will allow the water (superheated by the 9 bar pressure) to soak nicely through, spend about 25 seconds with the coffee in the gruppa, and make delicious coffee. A wrong grind will cause the water to spend too much time with the poweder (over-extracted) or too little (under-extracted)...both varieties of coffee will be undrinkable dreg.
But you are right, a hand pump machine like the La Pavoni, treated carefully and well, will produce exquisite coffee unlike any other.
Here are a couple of web resources:
www.gurus.net/pavoni - Daniel Ho, the owner of this site, is also a watch collector...lives in Toronto.