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The portafilter and basket are in direct contact with coffee oils and grounds every time you pull a shot. Rinsing under the tap is not enough — oils bond to the metal and turn rancid within days, adding a bitter, stale background to every subsequent shot. A proper cleaning routine takes about two minutes per day and ten minutes per week and makes a measurable difference to shot quality.
After each shot, the basket, portafilter body and the underside of the spout accumulate a thin film of coffee oil. This film oxidises quickly — within 24 hours at room temperature, yesterday's oil begins to smell and taste rancid. The filter basket itself has 150-200 tiny perforations that gradually fill with compacted coffee fines and oil. A partially blocked basket creates uneven flow, channeling and unpredictable shot times. The shower screen above the basket also collects grounds and oil that fall back upward during extraction.
Knock the puck out immediately after the shot — do not leave spent grounds in the basket, as they continue to transfer oil and moisture. Rinse the basket and portafilter body under hot running water, rubbing the inside of the basket with a finger or cloth to loosen loose grounds. Wipe the underside of the portafilter spout with a damp cloth. Lock the clean portafilter back into the grouphead while still hot — this keeps both the portafilter and grouphead at brewing temperature for the next shot. This entire routine takes about thirty seconds and prevents the worst of daily residue accumulation.
Once a week, remove the basket from the portafilter and soak both in hot water (not boiling) with a small amount of Cafiza or Puly Caff powder — roughly 2-3g per litre of water. Soak for 15-20 minutes. The detergent dissolves the oxidised oil that rinsing alone cannot reach. After soaking, scrub the basket perforations with a small brush — a dedicated basket brush or a clean toothbrush works well — and rinse thoroughly under hot water. Hold the basket up to a light source: you should be able to see through all the perforations. Blocked holes mean the soak was not long enough or the basket needs replacing.
The shower screen — the perforated metal disc in the centre of the grouphead — should be cleaned at the same time as the weekly portafilter clean. Remove it by unscrewing the central screw (many machines require a screwdriver or hex key). Soak it alongside the basket in the Cafiza solution, then scrub and rinse. Before refitting, wipe the area behind the shower screen in the grouphead — this is where grounds and oil collect most stubbornly and where neglect causes the worst taste contamination. Dry the screen before reinserting to prevent scaling on the surface.
Espresso baskets wear out. The perforations gradually enlarge with use and cleaning, and the internal shape of the basket can deform slightly over time. Signs of a worn basket include: shot times that keep getting faster despite finer grind settings, inconsistent extraction patterns visible through a naked portafilter, and visible distortion of the basket walls or an uneven top rim. Precision baskets — IMS, VST, Pullman — are manufactured to tighter tolerances than the stock baskets that come with most machines and make a meaningful difference to extraction consistency. A basket replacement costs 30-60 euros and can extend the useful life of an entry-level machine significantly.
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