What is a portafilter?

A portafilter is a handheld device specifically designed to hold coffee grounds during the espresso extraction process. It consists of a handle and a metal filter basket, where the finely ground coffee is placed and compacted (tamped) before being locked into the espresso machine. When hot water is forced through the coffee grounds at high pressure, it extracts oils and flavors, resulting in a rich and concentrated espresso shot.

The functionality of the portafilter is crucial to the espresso-making process, as it helps achieve the correct brewing pressure and water flow. By securely holding the coffee grounds and ensuring an even extraction, a well-designed portafilter contributes significantly to the quality of the espresso produced.

Other options do not accurately describe what a portafilter is, as grinding coffee is done using a grinder, a coffee brewing machine refers to the espresso machine itself, and serving espresso is an action related to the final product rather than the tool used for brewing.