Coffee and Espresso Machines Espresso machines use pressure in order to force water into finely ground and tamped beans. They create a rich, flavorful brew. Experts at the Good Housekeeping Institute recommend models that brew with a minimum pressure of 9 bars in order to get the best extraction. Beware https://www.coffeee.uk/products/swan-retro-pump-espresso-coffee-machine-blue-milk-frother