Moka pot and friends

Stovetop, not quite espresso

A moka pot — Alfonso Bialetti’s design from 1933 — pushes water up through the coffee using the steam and air trapped in its heated base.

A bar and a half, at best

It works at roughly 1–1.5 bar, a fraction of an espresso machine’s 9. So the cup is strong and heavy, but espresso it isn’t: there’s little or no crema, and it scorches easily if you let it run on.

Put the moka routine in order.

1. Fill the base to just under the valve
2. Fill the basket and level it off
3. Screw it together with a towel
4. Medium-low heat, lid up

Hot water, a fine grind, no tamp, medium-low heat and the lid up. Starting hot means less time on the flame and less time for the grounds to bake.

Why fill the moka base with water that is already hot?

Answer: Less time on the flame, so less baking. Less time on the flame. The base heats sooner, so the grounds spend less time baking — and less baking means less bitterness.

Stop before the sputter

The coffee starts as a slow trickle and speeds up as the base heats. When it begins to gurgle and spit, like a colonel at breakfast, the water is nearly gone and steam is forcing through the grounds.

Off the heat, then cold water

That stage is the one a lab study of moka pots linked to harsh, bitter, burnt-tasting compounds. Take the pot off just before it, and cool the base under a cold tap so the flow stops.

AeroPress, the espresso-ish one

Pressed by hand, an AeroPress reaches only about 0.25–0.5 bar, by its maker’s own figures. Its espresso-style recipe — about 18–22 g of fine coffee to 75–80 g of water, pressed after 30 seconds — makes a dense concentrate.

Lever machines — the design behind Gaggia’s crema-topped shots in the late 1940s — push the water with a spring or your own arm. Today’s small presses claim 6–9 bar, real espresso pressure, with a gauge to watch.

On a hand-lever press, what does the lever replace?

Answer: The electric pump. The pump. A spring or your arm supplies the pressure instead; they take practice and a capable grinder, and everything from lessons 1 to 3 applies.

Match each brewer to the pressure it reaches.

• AeroPress, by hand — 0.25–0.5 bar
• Moka pot — 1–1.5 bar
• Hand lever press — 6–9 bar
• Espresso machine — about 9 bar

Only the lever and the machine reach espresso pressure. The AeroPress makes a dense concentrate that holds up under milk, and its maker agrees it is not espresso.