How to Properly Maintain and Clean an Espresso Coffee Machine Espresso machines push water through the coffee grounds via pressure. This method of brewing creates more strength than drip coffee. The machines require 9 bars of pressure to extract flavor from the grounds. There are three major types of espresso https://www.coffeee.uk/products/de-longhi-barista-pump-espresso-machine-coffee-cappuccino-maker-black