How to Properly Maintain and Clean an Espresso Coffee Machine Espresso machines force water through the coffee grounds using pressure. This type of brewing makes a stronger beverage than drip coffee. These machines require 9 bar of pressure to extract flavor from the coffee grounds. Espresso machines are available in https://www.coffeee.uk/products/quest-36569-espresso-machine-with-milk-frother-15-bars-pressure