Tamping

Tamping is an important preparatory stage of making espresso, consisting in the even compression (pressing) of ground coffee in the portafilter with the help of a special tool — a tamper. Despite its simplicity, this step critically affects the quality of the drink.

The aim of tamping is to create a dense, even, and uniform coffee “puck” without voids or cracks. This is necessary for an even extraction: during brewing, the water under pressure must pass through all the coffee equally. If the coffee is compressed unevenly or has voids, the water will take “the path of least resistance” (a phenomenon called channeling), as a result of which one part of the coffee will be over-extracted (giving bitterness) and another under-extracted (giving sourness). Correct tamping requires even, vertical pressure with the same force. This seemingly small technical movement is one of the foundations of the barista's mastery and a guarantee of the balanced taste of espresso.