Coffee and Espresso Machines Espresso machines use pressure to force water through finely ground and tamped coffee beans. They produce a rich and delicious cup of coffee. Experts at the Good Housekeeping Institute recommend models that brew at a minimum pressure of 9 bars to get the most efficient extraction. https://www-coffeee-uk23398.fireblogz.com/61088171/10-tips-for-coffee-machines-espresso-that-are-unexpected