Description
High-pressure hot water extracts soluble compounds from finely ground coffee while emulsifying oils into colloidal suspension.
Technical
The 9-bar pressure forces water through densely packed coffee grounds at 92°C, creating turbulent flow that maximizes surface area contact. This extracts 18-22% solubles while shearing cell walls to release CO2 and lipids that form the crema emulsion.
Culinary Significance
Espresso's concentrated flavor and velvety texture form the base for milk drinks while showcasing a coffee's terroir. The rapid extraction preserves volatile aromatics lost in slower methods.
Science
Primary Reaction
Maillard Reaction
Parameters
Temperature
93°C optimal
90°C to 96°C range
Lower for lighter roasts, higher for darker
Time
27 seconds
25 seconds – 30 seconds
From first drop to stop
Equipment