Coffee and Espresso Machines Espresso machines make use of pressure in order to force water into finely ground and tamped beans. They create a rich, delicious brew. Experts at the Good Housekeeping Institute recommend models that brew with the minimum pressure of 9 bars in order to achieve optimal extraction. https://coffeee-uk14346.designertoblog.com/61239735/why-nobody-cares-about-espresso-machine