To descale an espresso machine, empty the water tank, fill it with a descaling solution made for espresso machines, run the solution through the group head, hot water outlet and steam wand, let it sit for 15–20 minutes, then flush the machine with at least two full tanks of fresh water. Most home machines need descaling every 1–3 months, depending on how hard your water is and how often you brew.
Always check your machine’s manual first. Many machines, including most Breville, De’Longhi and Philips models, have a built-in descale program that guides you through the steps.
Why descaling matters
Tap water contains dissolved minerals, mostly calcium and magnesium. When water is heated, these minerals form limescale inside the boiler, heating element, pipes and valves. Over time, scale:
- Lowers brewing temperature, which can make espresso taste sour.
- Slows water flow and reduces pressure.
- Makes the heating element work harder and use more energy.
- Can block small valves and the steam wand tip.
- Is a common cause of repairs that warranties may not cover if the manufacturer’s descaling instructions were not followed.
If your espresso suddenly tastes sour even though your grind and dose are unchanged, scale may be one cause. See our guide to sour espresso for others.
How often should you descale an espresso machine?
| Water hardness | Approx. mineral level | Descale every |
|---|---|---|
| Soft | Under about 60 ppm | 3–4 months |
| Medium | About 60–120 ppm | 2–3 months |
| Hard | About 120–180 ppm | 1–2 months |
| Very hard | Over about 180 ppm | Monthly, and consider filtered water |
Water hardness test strips cost a few dollars and often come with machines. Your local water utility may also publish hardness figures. If your machine has a descale alert, follow it, but set the water hardness in the machine’s settings first so the alert is accurate.
What to use to descale
- Manufacturer descaler: the safest choice. Breville, De’Longhi, Jura and others sell solutions or tablets made for their machines.
- Citric acid or lactic acid descalers: common in third-party espresso descalers and generally safe for most home machines when used as directed.
- Vinegar: usually not recommended. Many manufacturers advise against it because it can be harder to rinse out, leaves a smell, and may affect some seals and metal parts.
Never use descaler meant for kettles or toilets unless your manufacturer approves it. Some contain acids or additives that are not food-safe at espresso temperatures.
How to descale an espresso machine, step by step
These steps suit most single-boiler and thermoblock home machines. Follow your manual for timings and amounts.
What you need
- Descaling solution or tablets
- A large container (at least 1.5–2 liters) to catch water
- A cloth and fresh, filtered water
Steps
- Prepare the machine. Remove the portafilter, empty the drip tray, and take out any water filter from the tank. Filters can be damaged by descaler.
- Mix the solution. Fill the tank with water and descaler in the ratio on the package, often around 1 part descaler to 4–5 parts water, or one packet per liter.
- Heat up. Turn the machine on and let it reach temperature, unless your machine’s descale program says otherwise.
- Run solution through the group head. Place the container under the group and run about a third of the tank through it.
- Run solution through the steam wand. Open the steam or hot water valve for 20–30 seconds, then close it.
- Run some through the hot water outlet, if your machine has one.
- Let it sit. Turn the machine off and wait 15–20 minutes so the solution can dissolve scale.
- Finish the tank. Turn it on and run the rest of the solution through the group and wand, alternating.
- Rinse the tank well. Wash out any descaler residue.
- Flush with fresh water. Fill the tank with clean water and run it all through the group, wand and hot water outlet. Repeat with a second full tank. Use a third if you still taste or smell descaler.
- Reinstall the water filter (or a new one) and reset the descale alert if your machine has one.
Descaling dual boiler and heat exchanger machines
Machines with larger boilers, such as many prosumer heat exchanger or dual boiler models, often need a different process. Some manufacturers advise against acid descaling at home because scale flakes can block small parts, and they recommend using properly filtered or softened water instead. Others give a specific procedure involving draining the boilers. Always follow the manual for these machines, and consider professional service if you are unsure.
How to prevent scale in the first place
- Use filtered water. A filter pitcher or the machine’s in-tank filter reduces hardness. Replace filters on schedule, usually every 2–3 months.
- Avoid distilled or reverse osmosis water on its own. Water with no minerals can taste flat and may affect some machines’ sensors. Coffee-specific mineral packets added to distilled water are an option for enthusiasts.
- Empty the tank if you will not use the machine for a few days.
- Refill with fresh water daily rather than topping up old water.
- Set your machine’s water hardness so alerts match your water.
Water quality affects taste as much as gear. If you are setting up a new station, our guide on how to set up a home coffee bar covers water and placement.
Signs your machine needs descaling now
- Shots run slower even though grind and dose have not changed.
- The steam wand sputters or takes longer to reach full pressure.
- The pump sounds louder or strained.
- You see white flakes or a chalky film in the drip tray or water tank.
- Espresso tastes thinner, less hot or more sour than usual.
If you notice two or more of these, descale soon rather than waiting for the next scheduled date.
Descaling vs backflushing vs cleaning
| Task | What it removes | How often |
|---|---|---|
| Descaling | Mineral scale inside boiler and pipes | Every 1–3 months |
| Backflushing with detergent | Coffee oils in the group head and valve | Weekly to monthly (machines with a 3-way valve) |
| Wiping and purging | Grounds and milk residue | Every use |
Descaling does not remove coffee oils, and cleaning tablets do not remove scale. You need both. For a full routine, see the maintenance tips in our guide to making espresso at home. If your shots still taste harsh after cleaning, check our guide to bitter espresso.
FAQ
Can I use vinegar to descale my espresso machine?
Most manufacturers recommend against it. Vinegar can leave a lasting smell and taste, and may be harder on some seals and metals. Use a citric or lactic acid descaler made for espresso machines.
How do I know my espresso machine needs descaling?
Common signs include slower flow, lower steam power, louder pump noise, white flakes in the water, and espresso that tastes sour or less hot than before. Many machines also show a descale alert.
How long does descaling take?
Usually 30–45 minutes, including the resting time and two rinse cycles.
Do I need to descale if I use filtered water?
Yes, but less often. Most filters reduce hardness without removing it fully. Follow your machine’s alert or descale every 3–4 months.
What happens if you never descale an espresso machine?
Scale keeps building until it restricts water flow, lowers temperature and stresses the heating element and pump. Eventually the machine may stop heating or pumping properly and need professional repair.
Is descaling the same as cleaning?
No. Descaling removes minerals from inside the water system. Cleaning or backflushing removes coffee oils from the brew path. Both are needed.