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 from the Good Housekeeping Institute recommend models that brew with the minimum pressure of 9 bars to ensure the highest extraction. https://coffeee83644.dailyhitblog.com/35209714/20-fun-informational-facts-about-espresso-machine