Brew Pressure

The force pushing water through the coffee bed during espresso extraction, usually near the classic nine-bar target.

Filed under

What the machine does

What it means

The force pushing water through the coffee bed during espresso extraction, usually near the classic nine-bar target. Pressure shapes flow, contact time, and how the puck behaves under load. Treating it as the only adjustment leads to crude fixes — it matters most as part of a system, not as a single trophy number.

Keep going

Where this leads

Each one pushes this into the cup, compares it, or helps you act on it.

How the shot starts

Pre-infusion

Pressure only matters once the shot starts moving through the puck.

Use pre-infusion to smooth the beginning of the shot, not to compensate for careless preparation.

The numbers that define the shot

Dose

Pressure readings make more sense when the puck load is stable.

Use a scale for every dose when dialing in. Precision here saves time everywhere else.

How you read the result

Yield

Check whether the pressure change actually changed the result in the cup.

Think of yield as the result you are aiming for and brewed weight as the way you verify you hit it.

What people mean when they say "extraction"

Espresso Extraction

Move from machine pressure to what it changes in the cup.

Separate extraction from strength in your thinking. One asks how much was dissolved, the other how concentrated the drink feels.