A wet puck after a shot worries people more than it should.
Why it happens normally
No three-way solenoid valve. Machines without one — many entry-level and most thermoblock machines — do not release the pressure and water above the puck after the shot. It sits there and soaks in.
Machines with a solenoid vent that water to the drip tray, giving a dry puck.
This is a machine design difference, not a fault.
When it is a real signal
Puck soupy and the shot ran fast — under-dosed. There is too much headspace, so water pools above the puck.
Puck soupy and the shot tasted thin — likely channelling and under-extraction.
The dose test
Tamp, insert the portafilter, remove it. If the shower screen has left a deep imprint, the dose is too high. If there is no mark at all, it may be too low.
A small witness mark is about right.
What does not matter
A wet puck on a machine without a solenoid, when the shot tasted good. Nothing to fix.
Fixing it if you want to
Increase the dose by a gram to reduce headspace.
Add a puck screen, which also keeps the shower screen clean.
Wait a few seconds before knocking it out — some water drains back.
The rule
Taste the shot. If it is good, the puck is irrelevant.
Last reviewed 8 August 2026