Coffee and Espresso Machines Espresso machines make use of pressure to force water through finely ground and tamped coffee beans. They make a rich, tasty brew. Experts at the Good Housekeeping Institute recommend models that brew with a minimum pressure of 9 bars to achieve optimal extraction. Beware of companies https://www.coffeee.uk/products/amzchef-20-bar-espresso-maker-with-milk-frother