- Availability: Specialty
Pre-infusion gently saturates the coffee puck at low pressure (or with a brief pause after a small volume of water) before ramping to full extraction pressure. The wet puck swells and equalizes, which reduces channeling and produces a more even extraction. Newer prosumer and commercial machines (Slayer, La Marzocco Strada, Modbar, Decent) make pre-infusion a programmable variable; older single-boiler machines achieve a similar effect with line pressure.