Make sure the filter and gasket are in place in the upper chamber, and bring a pot of filtered water to a boil (212°F or 100°C).
Pour the coffee beans into a conical burr grinder and grind on a medium setting; a little finer than one would use for pour over. The grounds should slightly coarser than granulated sugar.
Fill the lower chamber with boiling water to just below the valve.
Pour the ground coffee into the funnel, tapping the side of the funnel to level the grounds and to remove any air pockets. Do not tamp down the grounds. Level the top with a knife.
Carefully place the funnel into the lower chamber, then securely screw the upper chamber onto the lower chamber, using a towel or oven mitts to protect your hands from the hot metal. Make sure there are no grounds on the gasket, threads, or the edge of the funnel.
Place the moka pot over low heat on an electric stove. If you're using a gas stove, keep the flame smaller than the base to protect the handle. After a few minutes on the heat, you'll hear the water starting to boil.
Once the coffee starts coming out of the center column, watch it carefully. If it shoots out violently, turn down the heat immediately. Once the upper chamber is half full of coffee, turn off the heat.
When the stream of coffee turns a honey color, immediately close the lid and remove from the heat. Stop extraction by submerging the lower chamber in a bowl of ice water, by wrapping it in a cold towel, or by running it under cold water.
Pour the coffee into demitasse cups and enjoy right away.