A portafilter (or group handle) attaches to the group head of semi-automatic and piston-driven espresso machines, and carries a tamped puck of coffee grounds within its basket. It is usually made of brass, and is attached by a plastic or wooden handle. The portafilter forms a seal with the espresso machine's gasket, and directs high-pressure hot water through the coffee puck.

After-market retailers also sell bottomless portafilters that minimize the espresso's contact with any metal. A bottomless portafilter is one tool baristas use to analyze the quality of the coffee grind and the evenness of the extraction.

External links

• Home-Barista article on using bottomless portafilters