How to descale a coffee maker, and how often you really need to
Scale makes coffee taste flat and slowly ruins the heater. How to remove it, how often to do it for your water, and why vinegar is a bad idea.
Thomas Walker
Ryan Mitchell, editor-in-chief
September 8, 2026
12 machines descaled in our test kitchen
This article explains a topic and doesn’t rank products. It links to our tests, and we may earn a commission through those links. Affiliate policy
In this article
Key takeaways
- Hard water means descaling every one to two months; soft water every four to six.
- Use the descaler your manufacturer recommends. Vinegar can damage seals and is hard to rinse out.
- A full descale takes about 30 minutes, most of it waiting.
- A water filter in the tank halves how often you need to descale.
Why scale matters
Tap water contains calcium and magnesium. When it heats up, those minerals settle as a white crust on the heater and in the pipes.
Scale insulates the heater, so the water doesn’t get hot enough and your coffee tastes flat. Eventually it blocks the flow completely.
How often to descale
It depends on your water hardness. Your water company publishes it, or a $5 test strip tells you in seconds.
| Water hardness | Grains per gallon | Descale every | With a filter |
|---|---|---|---|
| Soft | Under 3.5 | 4–6 months | 6–12 months |
| Moderate | 3.5–7 | 2–3 months | 4–6 months |
| Hard | 7–10.5 | 1–2 months | 3–4 months |
| Very hard | Over 10.5 | Monthly | 2 months |
Based on about two cups a day.
Step by step
- Empty and rinse
Empty the drip tray, grounds container and water tank.
- Mix the descaler
Dissolve the descaler in the tank with the amount of water on the label.
- Start the program
Most bean-to-cup machines have a descale program; it pauses so you can empty the tray.
- Rinse twice
Fill the tank with fresh water and run the rinse at least twice.
- Reset the reminder
Most machines count down to the next descale; reset it in the menu.
Vinegar or descaler?
Vinegar works on a simple drip coffee maker, but it’s a weak acid, so it needs more time, and the smell lingers for several brews.
Myths, checked
Mineral water contains minerals too. Only filtered or soft water slows scale down.
Descaling removes minerals; cleaning removes coffee oils. You need both.
Some machines make descaling much easier than others. See how they compared in our tests.
Terms explained
Frequently asked questions
What happens if I never descale?
Can I descale with lemon juice?
Thomas spent six years as a line cook in restaurants in Chicago and New York. Since 2020 he has tested kitchen appliances for BrasQ, from air fryers to coffee makers. He holds an SCA certificate in barista skills.
- Checked and updated.
- First published.
- BrasQ bean-to-cup test protocol (2026)
- US Geological Survey: Hardness of water
- Manufacturer manuals