What is puck prep for espresso?

Puck prep is the process of preparing the coffee grounds in the portafilter before brewing: distributing the grounds evenly, removing clumps (using a WDT tool), and tamping with consistent pressure. Good puck prep is essential for even extraction — an uneven puck channels water unevenly. A typical routine: dose into basket, run WDT tool through grounds, level/distribute, tamp with 15–20kg of pressure, then lock into the machine.