EspressoFit

Groupheads, explained

The grouphead (or brew group) is the part of the machine the portafilter locks into — where hot water is delivered to the coffee. It matters for two reasons: the type of group tells you a lot about how the machine holds temperature, and it decides which group parts — shower screens and group gaskets — fit, which is a different question from portafilter size.

The main types

Why group parts fit by grouphead, not portafilter size

A basket or tamper is sized to the portafilter. But a shower screen (the perforated disc water passes through) and a group gasket (the seal the portafilter presses against) sit in the group itself — so they fit by the grouphead, not the portafilter diameter. That's why two 58mm machines can need different shower screens if their groups differ, and why we key these parts to the group standard rather than a millimetre size.

Group parts in the database (16)

Groups in the database

How we verify

Each machine's group is recorded from its manufacturer source on the entry. See how we verify compatibility.