The puck is wet and soupy after the shot
Knocking out the portafilter reveals a sludgy, waterlogged puck rather than a firm one that releases cleanly.
Applies to: Espresso machine, Espresso
Likely causes and adjustments
Try one adjustment at a time so you know what actually changed the result. Start with the first cause below — if it doesn't help, reveal the next.
Cause 1 of 3 · Commonly the cause
Normal behaviour on a machine with no three-way valve
Did the espresso itself taste as expected?
Many machines leave water above the puck by design. A wet puck alone is not a fault if the shot tasted right.