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://www-coffeee-uk81117.blog-ezine.com/29877880/how-to-get-more-benefits-out-of-your-espresso-machine