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Espresso Extraction Theory

Imaginary
Puck Resistance

Understand pressure curves, master the craft

01

Basics

In extraction,
puck resistance is dynamic

02

Dynamics

Water flows through,
resistance decreases
pressure reacts

03

Core Concept

We can imagine a
puck pressure curve
from 15 bar to 6 bar

(Actual resistance varies by grind and dose)

Imaginary Puck Resistance Curve

Start End
04

WD Impact

Higher WD means
actual pressure catches up fast
to the curve

Actual vs Imaginary Curve

Imaginary
High WD
Low WD
05

Maintenance

Faster catch-up,
longer high pressure
fuller extraction

High Pressure Duration

High WD
Low WD
06

Flavor Results

WD determines flavor vividness

High WD

Higher overall pressure
Vivid and sharp traits
Distinct layers

Low WD

Gentle pressure rise
Soft and round flavor
Integrated mouthfeel

07

Headspace

Larger Headspace,
longer fill time
shifts curve to the right

Headspace Impact on Pressure

Small HS
Large HS
Start End
Group Head Small Puck

Small Headspace

Fast pressure build

Group Head Large Puck

Large Headspace

Fill space first

08

Tamping

Tamping method
also shapes the
imaginary curve

Heavy Tap Solid Structure Light Tap Loose Structure Imaginary Curve
09

Scale of Diff

Tamping effect is
more subtle than WD
needs A/B Testing

Influence Comparison

∞

Puck Resistance
is the language of pressure

Distribution shapes it, WD scales it.
Every shot tells a unique story.

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