Coffee and Espresso Machines Espresso machines make use of pressure to force water through finely ground and tamped coffee beans. They create a rich and flavorful brew. 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-uk51020.blogpostie.com/51953831/coffee-machines-espresso-tips-from-the-top-in-the-business