Espresso is a highly concentrated coffee made by forcing pressurized hot water through finely-ground coffee using an espresso machine. A single shot of espresso measures approximately 1 ounce, while a double shot of espresso has about 2 ounces of liquid. It serves as a base for many of your favorite coffee drinks, like lattes, cappuccinos, and americanos. Choose one from our list of the best coffee beans for espresso.