How to Descale an Espresso Machine: Step-by-Step Guide

Why descaling matters

Limescale builds up inside the boiler and water lines every time you pull a shot. Even with soft water, minerals accumulate. Left alone, scale insulates heating elements, slows temperature recovery, narrows water paths, and gives your espresso a flat, almost chalky taste. Descaling is the process of dissolving those mineral deposits with a mild acid solution, and it is the single most important piece of maintenance any home barista can do.

How often to descale

There is no single number. The honest answer depends on your water hardness and how much you actually use the machine. A few practical signals to watch for:

• The machine takes noticeably longer to heat up than it used to
• The pump sounds louder or labored when you pull a shot
• Shots taste duller even when the puck prep is good
• The water tank or drip tray shows visible white flecks or crusty residue

If your tap water is hard (above 180 ppm), expect to descale every 2 to 3 months. With soft water or a good filter, every 4 to 6 months is usually fine. The cheapest and most accurate test is a small TDS meter — check the water coming out of your machine a few seconds into a shot. If the reading climbs into the 150s and stays there, scale is forming.

What to use

Skip vinegar. It works in a pinch but leaves an odor that takes days to clear, and the acetic acid is aggressive enough to eat rubber gaskets over repeated use. Use a dedicated descaler — citric acid-based products are gentler on seals, while lactic and glycolic blends (often marketed as professional) work faster on heavy buildup.

A few reliable options sold widely in the US and Europe include Durgol, Urnex Dezcal, and the official Breville cleaning tablets for Breville machines. Whatever you pick, follow the dilution ratio printed on the bottle. More is not better.

The actual descaling process

1. Empty the drip tray and water tank. Remove any water filter from the tank.

2. Fill the tank with fresh water plus the descaler, in the ratio printed on the label.

3. Place a large cup (at least 500 ml) under the group head and the steam wand.

4. Run the machine's built-in descaling program if it has one. If it doesn't, manually run water through the group head in 30-second bursts, pausing for a minute between each, for roughly 10 minutes total.

5. Open the steam wand valve to draw descaler through the boiler. Let it run until the tank is empty.

6. Rinse thoroughly. Refill with clean water, run it all through the group head and steam wand, and repeat at least twice. Skipping this step is the most common reason people end up with sour-tasting espresso for a week.

Common mistakes

• Not rinsing enough. Two rinses is the bare minimum. Three is safer.
• Using hot water in the tank. Some machines (especially Breville) warn against this — it can trigger the thermal fuse prematurely.
• Forgetting the steam wand. Most of the mineral buildup lives in the steam side, not just the brew side.
• Descaling with the portafilter locked in. Remove it. A blind basket is for backflushing, not descaling.

When one cycle isn't enough

If your machine has never been descaled in years, or if the pump sounds like it's straining, one descaling cycle may not be enough. Run the full process twice in a row, with a clean rinse in between. If performance still doesn't recover, the scale may have moved somewhere it shouldn't have — at that point, send us a message through the contact form with the make and model, and we'll help you figure out the next step.

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Need help with a specific machine? Tell us the make and model in the contact form and we'll send back a tailored descaling plan, including which product to use and how often for your water.