Tips for Stovetop Coffee

Giorgio Milos on the Atlantic Food Channel lays out the proper way to make coffee in one of those silver Moka pots that many of us have for making espresso at home:

While the process is simple to understand, knowing some finer points makes all the difference. First and foremost is grind. If you have a home grinder, go for medium. Too fine of a grind, like you'd use for espresso, results in a burnt and bitter taste from water passing through the ground coffee too slowly, causing over-extraction. Beans ground too coarsely, as for French press, produces an overly light body and sour taste, as water passing through the grounds too quickly leads to under-extraction.

Important: do not press (tamp) the coffee in the filter. If you do, the pressure won't be sufficient for the rest of the process to work properly, leading once again to over-extraction. If you prefer a stronger flavor profile, fill up the filter just up to its capacity, not more and not less. Fill the lower chamber with cold water up to the valve or marked line—read the manual carefully—and set it on a low flame, properly extracting the coffee slowly at a lower temperature.

Critical final step: turn off the flame when the upper section is half full, to avoid overheating and burning the coffee. As the water approaches boiling, which you don't want to happen, the process rapidly accelerates, extracting bitter, unpleasant flavors—creating a burnt taste—and upsetting the beautifully balanced aromatic equilibrium the Moka method is known for. That hiss my grandmother took as "coffee's done" signal comes from steam, and steam burns coffee.

I was already well aware that "boiling is bad" for coffee... but I had always thought you wanted as fine a grind as possible for espresso. Maybe that's only for the machines? What only just occurred to me (since it's Anna who makes the espresso) is that this is exactly the same procedure I do for my vacuum pot to make "regular" coffee... except there too fine a grind risks clogging the gasket/filter. I suppose the Moka gets to a much higher pressure in order to make espresso possible?

photo by Flickr user globevisions used under a Creative Commons license