Coffee and Espresso Machines Espresso machines make use of pressure in order to make water into finely ground and tamped beans. They produce a rich, delicious cup. Experts from the Good Housekeeping Institute recommend models that brew with the minimum pressure of 9 bars in order to achieve optimal extraction. https://coffeee35685.ampedpages.com/this-is-the-complete-guide-to-coffee-machines-espresso-57069154