parmalee
07-25-09, 02:34 PM
Lately I've been rather obsessed with the moka pot/stovetop espresso maker--I'm a coffee roaster, incidentally. The reason that coffee brewed in this fashion does not constitute the consensual defintion of "true" espresso is primarily that such a method cannot produce sufficent pressure: a proper boiler-and-pump espresso machine can produce 8-9 bars of pressure (well, they can actually produce a good deal more, but 8-9 bars is optimal), whereas a moka pot is estimated to produce a mere 1-1.5 bars of pressure. Consequently, the quality and quantity of the crema produced is inadequate. There are other factors which constitute "true" espresso--water temperature, pre-infusion time, as well as matters pertaining to the coffee itself--but as regards the moka pot, pressure is the most critical issue.
Is there a means to manufacture such a device, using essentially the same principles (boiler, but no pump), that can produce considerably greater pressure? Bialetti has developed the Brikka--http://www.bialettishop.com/BrikkaMain.htm--but it relies upon a special valve at the top which simply increases the pressure following the actual extraction process in order to produce a sort of faux crema. Then there is the lovely Automic Coffee Maker:http://www.atomic.org.nz/index.html, http://www.atomiccoffeehouse.com/about.html:
http://www.atomiccoffeehouse.com/images/gallery01.jpg
The Atomic coffee maker employs a small hole in the water tube that serves to increase pressure pre-extraction, and the long tube allows for the water to cool somewhat before wetting the grounds--another problem with moka pots is that the water is simply too hot. It purportedly produces 4-6 bars of pressure.
So does anyone have any idea as to how one would go about increasing pressure even more without employing a pump?
Is there a means to manufacture such a device, using essentially the same principles (boiler, but no pump), that can produce considerably greater pressure? Bialetti has developed the Brikka--http://www.bialettishop.com/BrikkaMain.htm--but it relies upon a special valve at the top which simply increases the pressure following the actual extraction process in order to produce a sort of faux crema. Then there is the lovely Automic Coffee Maker:http://www.atomic.org.nz/index.html, http://www.atomiccoffeehouse.com/about.html:
http://www.atomiccoffeehouse.com/images/gallery01.jpg
The Atomic coffee maker employs a small hole in the water tube that serves to increase pressure pre-extraction, and the long tube allows for the water to cool somewhat before wetting the grounds--another problem with moka pots is that the water is simply too hot. It purportedly produces 4-6 bars of pressure.
So does anyone have any idea as to how one would go about increasing pressure even more without employing a pump?