Coffee and Espresso Machines Espresso machines make use of pressure in order to push water into finely roasted and tamped beans. They make a rich and tasty brew. Experts at the Good Housekeeping Institute recommend models that brew at a minimum pressure of 9 bars to ensure the highest extraction. https://www-coffeee-uk52992.ssnblog.com/29234680/5-coffee-machines-espresso-instructions-from-the-professionals