Preinfusion
Preinfusion is the initial stage of espresso extraction, at which hot water is introduced into the dry coffee grounds at low pressure to saturate the coffee puck and remove CO₂, preparing for the brewing process.
This process helps prevent water from flowing through low-resistance channels, ensuring even coffee expansion and stable extraction for better flavor.
Preinfusion is a feature commonly found in professional Espresso machines, helping to produce a smoother, more balanced, and higher-quality cup of coffee.