Refers to the process of infusing coffee with hot water. Hot water releases or “extracts” the flavor from the roasted, ground coffee. The term is used mostly with espressoA small coffee beverage, about 20 ml, prepared on an espresso machine where pressurized hot water extracted through compressed coffee.: In its most stripped-down, basic form, this is a working definition for espresso: A small More, adding pressure to the mix as brew variables.