A thorough knowledge of the science of coffee is required for the professional preparation of espresso specialties. The barista can discern the differences between different types of coffees and different types of roasts. This professional knows which exact mixture to select for each specialty. High-quality espresso machines allow for the slightest adjustments in coffee quantity, temperature, and pressure. The well-trained barista can reset the machine for every specialty, achieving the perfect results for the respective mixture. Characteristic of the barista’s work is that he does not let the machine prepare the finished beverage, but rather prepares every cappuccino, Latte Macchiato, or similar specialties by hand from freshly prepared espresso and milk foam.