Coffee and Espresso Machines Espresso machines use pressure to force water into finely ground and tamped beans. They produce a rich, tasty brew. Good Housekeeping Institute experts recommend models that use 9 bars minimum to ensure a perfect extraction. Beware of manufacturers who tout more pressure than is required. Types https://www-coffeee-uk51582.blogvivi.com/30344008/the-reasons-coffee-machines-espresso-is-more-dangerous-than-you-realized