If you're looking to diversify your coffee beverage options, it's time to invest in an espresso machine. Espresso is a form of coffee that is finely ground and brewed with a small amount of almost boiling water.Each cup of espresso has the same amount of caffeine as a standard cup of coffee, resulting in a stronger flavor. To counteract the bitterness, add milk to espresso for popular drinks like Cappuccinos, Lattes, and Macchiatos