The espresso guide

What espresso is

Espresso is a small, concentrated coffee produced by forcing hot water (~93 °C) under pressure (~9 bar) through a compact puck of finely ground coffee. Typical extraction time: 25–32 seconds.

The four levers

1. Dose — grams of dry coffee in the basket.
2. Yield — grams of liquid espresso in the cup.
3. Time — seconds from pump start to end of pour.
4. Grind — fineness. Your primary control for time.

Water temperature and pressure are usually fixed by the machine.

A starting recipe

• Dose: 18 g
• Yield: 36 g (a 1:2 "normale" ratio)
• Time: 25–30 seconds
• Water: 93 °C at 9 bar

Weigh both dose and yield. Time the shot. Adjust grind until 18 → 36 g lands in 25–30 seconds.

Diagnosing a shot

• Sour, thin, fast (< 22 s) — under-extracted. Grind finer.
• Bitter, dry, slow (> 35 s) — over-extracted or choked. Grind coarser.
• Right time, still off — adjust ratio: pull longer (1:2.5) for brightness, shorter (1:1.5) for intensity.

Everything else — pre-infusion, pressure profiling, distribution tools — is refinement on top of these four levers.