Coffee and Espresso Machines Espresso machines make use of pressure to force water through finely ground and tamped coffee beans. They make a rich, flavorful brew. Experts at the Good Housekeeping Institute recommend models that brew at a minimum pressure of 9 bars in order to achieve optimal extraction. Beware https://www-coffeee-uk00639.blogoxo.com/29907645/10-tips-for-coffee-machines-espresso-that-are-unexpected