How-to guide
Fall is the time to descale your espresso machine. Here's how.
Why scale builds up, how often to descale by water hardness, general steps, and what each brand's manual covers.
This is a general how-to, not a model-specific procedure. Your machine's manual comes first; where it differs from this page, follow the manual. We show no star ratings or review counts. Some links may earn us a commission; see the disclosure.
Why descale
Tap water carries dissolved minerals, mostly calcium and magnesium. Heating water leaves some of them behind as scale inside the boiler or thermoblock, pipes and valves. Scale can slow water flow, affect brew temperature and, left long enough, block parts. Descaling dissolves it. Fall is a handy reminder: do it before the holiday stretch when the machine gets more use.
How often, by water hardness
The USGS Water Science School classes water hardness (as calcium carbonate) like this.
| USGS class | Hardness (mg/L) | What it means for descaling |
|---|---|---|
| Low hardness | 0 to 60 | Scale builds slowly. Follow the longest interval your manual allows. |
| Moderately hard | 61 to 120 | Follow your manual’s schedule or descale alert. |
| Hard | 121 to 180 | Expect to descale more often. Set the machine's water hardness setting if it has one. |
| Very hard | Over 180 | Descale as often as the manual says for hard water, and consider filtered water. |
Hardness classes from the USGS. Intervals are not ours to set: many machines let you enter your water hardness and then prompt you when to descale.
General descaling instructions
The usual shape of a descale. Your manual’s steps and amounts win.
- Read the descale section of your manual and get the descaler it names.
- Empty the drip tray, remove the portafilter, and take any water filter out of the tank (most manuals say to).
- Mix the descaler with water in the tank, in the ratio on the descaler's label or in the manual.
- Put a large container under the group head and the steam wand.
- Start the descale cycle if your machine has one. If not, run the solution through the group head and steam wand in short bursts as the manual describes, letting it sit between bursts if told to.
- Empty and rinse the tank, fill it with fresh water, and flush the group head and steam wand until the water tastes and smells clean. Repeat the rinse if the manual says so.
- Refit the water filter, wipe down, and pull a test shot you are willing to pour away.
Maker prices, dated. No brand-paid placements.
Brand notes for machines we cover
- Breville: follow the descale steps in the manual for your exact model (for example Breville Bambino, Breville Barista Express, Breville Barista Pro, Breville Dual Boiler). Use the descaler the manual names, and run the built-in descale cycle if your model has one. We do not reproduce model-specific procedures here.
Find your manual on the maker's support site using the model number on the machine's label. Links above go to our machine pages, which link to each maker's product page.
Descaler vs vinegar
Vinegar is often suggested online, but some espresso machine makers advise against it in their manuals, and it can leave a smell that takes several rinses to clear. A descaler sold for espresso machines, or the one your manual names, is the safer choice. Do not mix descalers, and never use bleach or other household cleaners in the water path.
No price shown: we have no checked price for a descaler yet, so we show none rather than guess.
Filtered water tips
- If your machine takes a tank filter, use the type the manual names and replace it on the schedule it gives.
- A pitcher or under-sink filter can reduce some minerals; check what the filter is rated to remove.
- Do not use distilled or fully demineralized water unless your manual allows it; some machines rely on minerals for water level sensors.
- Filtered water slows scale; it does not replace descaling.
No price shown: we have no checked price for a water filter yet.
See also: the best knock boxes and espresso cleaning supplies (descaler picks with maker prices), the espresso accessories starter kit (cleaning supplies), all espresso machines, best espresso machines and the espresso recall checker.
FAQ
How often should I descale my espresso machine?
Follow your manual first; many machines show a descale alert. As a rule, the harder your water, the more often scale builds up, so hard-water homes descale more often than low-hardness-water homes.
Can I descale with vinegar?
Check your manual before you do. Some espresso machine makers advise against vinegar, and using a product your manual does not approve may matter for warranty. A descaler made for espresso machines is the safer default.
How do I know how hard my water is?
Your water utility's annual water quality report usually lists hardness. Test strips are another option. The USGS classes water above 120 mg/L as calcium carbonate as hard.
Does filtered water mean I never need to descale?
No. A filter can slow scale buildup, but most water still carries some minerals. Keep descaling on the schedule your manual gives.
Is descaling the same as backflushing?
No. Descaling removes mineral scale from the water path. Backflushing cleans coffee oils from the group head on machines that support it. Your manual says which your machine needs and how often.
Have you tested these steps on each machine?
No. This guide gives general steps; your machine's manual is the authority.
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