Coffee and Espresso Machines Espresso machines make use of pressure to force water through finely ground and tamped coffee beans. They produce a rich, delicious brew. Experts from the Good Housekeeping Institute recommend models that brew at the minimum pressure of 9 bars to get the most efficient extraction. Beware https://www.coffeee.uk/products/gaggia-deluxe-coffee-machine-1850-w-15-bar