How do I fix a clogged espresso machine?

A clogged espresso machine is one of the most common frustrations for home baristas, but it is almost always a symptom of either improper grind settings or a buildup of coffee oils and mineral deposits. When your machine struggles to dispense espresso, the first step is to evaluate your grind size. If the particles are too fine, they create excessive resistance, effectively choking the machine. Adjusting your grinder to a slightly coarser setting often resolves the issue immediately.

If the grind is correct but the flow remains restricted, the culprit is likely a dirty group head. Over time, coffee oils and fine particles accumulate on the shower screen and within the internal dispersion paths. To address this, you should perform a backflush. By using a blind filter—a basket without holes—and a specialized espresso machine cleaning powder, you force pressurized water and detergent back through the group head's internal valves, dissolving the stubborn residue that a simple rinse cannot reach.

Beyond the group head, mineral buildup from your water supply can cause internal blockages. If you live in an area with hard water, limescale can accumulate in the boiler and valves, leading to reduced pressure and inconsistent flow. Regular descaling is essential to dissolve these mineral deposits and keep the internal circuits clear. Always follow the manufacturer's guidelines for your specific machine, as some require specific descaling agents to avoid damaging internal components.

Finally, don't overlook the physical components. The shower screen and the group gasket can become physically obstructed by old grounds or worn out over time. If you notice water leaking around the portafilter or uneven extraction, it may be time to remove the shower screen for a deep scrub or replace the gasket entirely. Consistent maintenance—purging the group head after every shot and performing a weekly backflush—is the best way to ensure your equipment remains in top condition and your espresso stays delicious.