Espresso is more than just strong, dark coffee. Real espresso, which is key to making Tiramisù, is rich, creamy, and full-bodied, with an intensely deep flavor. It all begins with the right coffee beans and proper roasting.
Typically, espresso is made with a carefully selected blend of arabica coffee beans from different regions (arabica and robusta are the only two varieties of coffee bean). The beans are roasted in machines that bring them to progressively higher temperatures (usually not more than 450ºF) to create the right balance of acidity and bitterness. True espresso roast is not as bitter or as darkly roasted as many people think. It really only ranks medium to dark on the coffee-roasting continuum—French roasts are actually much darker.
While using the right coffee is the first step to great espresso, using the right grind and brewing method is just as important. Espresso is traditionally made with a machine that heats the water to an exact temperature and forces it at a precise pressure through the beans, which are finely ground and carefully tamped to prevent water from moving through them too quickly. The entire process is truly “express”—only 25 to 30 seconds from start to finish.