Descaling
Descaling is the process of removing mineral deposits — primarily calcium carbonate (limescale) — that accumulate inside coffee equipment over time. Every time water is heated in a kettle, boiler, or brewing chamber, dissolved minerals precipitate out and form a hard, chalky buildup on internal surfaces. Left unchecked, limescale restricts water flow, reduces heating efficiency, causes temperature instability, clogs valves and tubing, and ultimately damages the equipment. Descaling is the single most important maintenance task for any coffee machine that uses heated water.
The rate of limescale buildup depends directly on your water hardness. Hard water (above 150 ppm total hardness) can cause noticeable buildup within weeks of regular use, while soft water may allow months between descaling cycles. Signs that your equipment needs descaling include: slower brew times, reduced water flow, lower water temperature, unusual noises during heating, visible white deposits around the showerhead or steam wand, and a decline in coffee taste quality — particularly increased bitterness or a chalky mouthfeel.
Descaling solutions dissolve limescale through acid reactions. Commercial descaling products (like Dezcal, Durgol, and manufacturer-branded solutions) use food-safe acids — typically citric acid or lactic acid — formulated for safe contact with machine internals. White vinegar (acetic acid) works as a budget alternative but is less effective, slower-acting, and can leave a lingering smell that requires extensive rinsing. Citric acid powder dissolved in water is a popular middle ground between commercial products and vinegar.
The descaling process varies by equipment type but generally involves running the acid solution through the machine's water system, allowing it to soak and dissolve deposits, and then flushing thoroughly with fresh water until all traces of the solution are removed. Espresso machines with boilers may require a longer soak time. Always consult your machine's manual for model-specific descaling instructions, as some internal components (like certain gaskets or coatings) may be sensitive to strong acids.