A tamper is a device used for compacting the coffee grounds when brewing espresso. The “tamping” operation is one of the most important steps in espresso brewing. During tamping, the coffee grounds are pressed in to the filter basket, compacting them into a puck. The coffee needs to be compacted in order to create enough pressure for a correct extraction during shot pulling.
The tamper has a flat side which is used to press onto the coffee grinds, and a handle. The flat side is made of metal, stainless steel and aluminium are most commonly used. The handle can be made from the same material as the tamping side, but many times it can be made of wood, or plastic.