Pre-Infusion

Pre-infusion is a technique used in espresso brewing where a small amount of water at low pressure is applied to the coffee grounds before full pressure extraction begins. This allows the coffee to bloom (release CO2) and become evenly saturated, reducing channeling and improving extraction uniformity. Pre-infusion typically lasts 3-10 seconds at 1-3 bars of pressure before ramping up to full 9 bars. Many modern espresso machines have built-in pre-infusion, while manual machines require the barista to control it. Pre-infusion is especially beneficial for light roasts and can help achieve more even extraction and better flavor clarity.