A portafilter that drips after the shot ends — or leaks around the edge while locked in — is one of the most common and most fixable espresso faults. In most cases the cause is not the machine failing but the seal: a dirty or worn gasket, an incompletely locked portafilter, or a basket that is not seating correctly. This guide walks through the seal-and-maintenance checks in order so the dripping stops without unnecessary repair.
The direct answer: check the gasket, the lock, and the basket
Work through three checks: inspect and clean the group head gasket, confirm the portafilter locks in fully (not at an angle or under-locked), and verify the basket is the right size and seated in the portafilter. The gasket is the usual culprit — a dirty or worn gasket breaks the seal and lets water escape. If cleaning and re-seating do not stop the drip, the gasket likely needs replacing, which is a common, low-cost service part.
Check 1: the group head gasket
The gasket is the rubber ring inside the group head that the portafilter seals against. The NCA brewing essentials and the Specialty Coffee Association frame the seal as part of consistent extraction, and James Hoffmann has covered portafilter sealing at home. Over time it collects coffee oils and wears flat, and either condition breaks the seal — which is exactly the drip you see under or around the portafilter. Wipe the gasket clean with a damp cloth, and if it looks worn, hard, or grooved, plan a replacement. The machine cleaning guide and the group head guide on this site cover the routine and the parts.
Check 2: the lock
Even with a good gasket, a portafilter that is not locked in fully will drip. Insert the portafilter straight and rotate it firmly until it stops — the handle should sit at the expected position, not hang loose or force past it. If the lock feels wrong, the gasket may be swollen with oils or the portafilter may be the wrong size for the group. Re-seating after a clean gasket fixes most false-lock drips.
Check 3: the basket
A basket that does not seat properly in the portafilter — a worn rim, or the wrong basket for the portafilter — can let water pass around the coffee instead of through it, which reads as dripping or uneven flow. Confirm the basket sits flush with the portafilter rim and clips in without wobble. If the basket is loose or the rim is damaged, replace it; the portafilter and basket size guide on this site helps match the parts.
When it is not a seal problem
If the seal is clean and the lock is solid, but water still drips or sits in the basket, the cause is the coffee bed, not the hardware: Perfect Daily Grind’s cleaning guide covers the basket upkeep, and the NCA water guide explains the water variable. a grind too fine or a dose too high stops flow and leaves water sitting — a symptom covered in the slow extraction guide on this site. For larger water accumulation, the leak triage guide covers the machine-side causes. The distinction matters because a bed fix is cheap and instant, while a hardware fix is a service item.
Prevention is the quiet half of fixing a dripping portafilter. A quick daily habit of wiping the gasket dry after use and locking the portafilter in without twisting the basket keeps both surfaces clean, and a monthly visual check of the gasket catches wear before the seal fails mid-shot. The drips that develop slowly — slightly longer or messier each week — are almost always a warn-out gasket announcing itself; catching it early turns a five-minute replacement into a non-event, while delaying turns the same part into a messy counter and a confused morning. Add the check to your standard cleaning routine and the dripping portafilter stops being a recurring fault entirely.
One more check worth doing when the drip appeared suddenly: confirm the basket is actually the right one for the machine and the portafilter. A mismatched basket — too small, a tortured lip, or the wrong width — will never seal properly no matter how new the gasket is, and it can produce the “leaking portafilter” symptom even on a healthy machine. Match the parts before replacing anything expensive; a quick size check against the machine manual or the parts guide on this site often resolves the drip for free.
Frequently asked questions about portafilter dripping
My portafilter is leaking. What can I do to fix it?
Check the group head gasket first — clean it, then replace it if worn. Confirm the portafilter locks fully and the basket seats properly. Those three cover most leaks.
Why is my espresso dripping instead of flowing?
Dripping usually means the grind is too fine or the dose too high, so water barely passes. Coarsen the grind or reduce the dose; if it persists, check the pressure and group.
What is the 30 second rule for espresso?
A dial-in benchmark: a standard double shot finishes in roughly 25–30 seconds. It is a starting extraction range, separate from sealing.
Why is water staying in my portafilter?
Water that sits in the basket usually means the bed is so fine or full that flow has stopped, or the basket holes are blocked. Loosen the grind, check the dose, and clean the basket.
Seal first, then troubleshoot
Portafilter dripping after brewing is almost always a seal or maintenance issue near the group head — the gasket, the lock, or the basket. Clean, re-seat, and replace the cheap part before suspecting the machine. If the checks pass and the drip continues, move to the bed and machine troubleshooting with the guides above — and the accessory collection has the baskets and cleaners to keep the seal fresh.
