Coffee and Espresso Machines Espresso machines use pressure to make water into finely ground and tamped beans. They make a rich, delicious brew. Good Housekeeping Institute experts recommend models that are brewed at 9 bars minimum for a perfect extraction. Beware of brands that advertise more pressure than is required. https://coffeee70961.is-blog.com/36106200/there-s-a-good-and-bad-about-coffee-machines-espresso