Espresso is not a type of bean or roast, but rather a method of brewing coffee. It involves forcing hot water through finely ground coffee beans at high pressure, resulting in a concentrated and flavorful shot of coffee.
While the term "espresso" is often used to refer to a type of coffee bean or roast, it is actually a style of brewing that can be used with any type of coffee bean. In fact, many espresso blends are actually a blend of different types of beans, carefully selected and roasted to create the perfect flavor profile for espresso.
The key to making a good espresso is to use freshly roasted, high-quality coffee beans, and to grind them finely in order to maximize the surface area that the hot water comes into contact with. The water should be heated to around 200 degrees Fahrenheit, and should be forced through the coffee grounds at high pressure (usually around 9 bars) using an espresso machine.
The result is a concentrated shot of coffee with a rich, creamy crema on top. Espresso is often used as the base for other coffee drinks, such as cappuccinos and lattes, and is also enjoyed on its own as a shot of pure coffee flavor.
So, to sum it up, espresso is not a type of bean or roast, but rather a method of brewing coffee that results in a concentrated and flavorful shot. It can be made with any type of coffee bean, and the key to a good espresso is using high-quality beans and grinding them finely.