Tamp: (v.) to precisely press your espresso grounds into a perfect puck.
The key to really tasty espresso is even extraction. Hot water is being forced through super-fine coffee grounds at 9 bars of pressure, so every little bump and valley in the surface of the coffee grounds affects the way the espresso tastes. This is why we tamp. The tamp levels out the grounds and presses them down evenly, forming a consistent puck. When tamping, it’s important to have the correct form. Our baristas tamp and pull hundred of espresso shots a day, and repetitive stress injury is so real. When tamping, your wrist and arm should be a straight, upward extension of the tamper, with your elbow at a 90 degree angle (pictured).