The answer in 30 seconds
- 💧 With hard water, descale every 2 to 3 months; with soft water, every 4 to 6 months.
- ⏱️ Slower flow, lukewarm coffee, noisier pump: the machine is already scaled up.
- 🍋 Food-grade citric acid, about 20 g per litre of lukewarm water, does the job for next to nothing.
- 🚫 White vinegar is not recommended by most manufacturers: it attacks seals and leaves a stubborn smell.
Updated 27 September 2026 · Reading time: 7 min
In Morocco, tap water is often hard, and it is the leading cause of breakdowns in home coffee machines. It has nothing to do with the quality of the coffee or the machine: it's maintenance, and it can be planned. This article explains how often to descale, how to go about it, and when the problem is no longer limescale.
Why limescale damages a machine
Limescale builds up on the heating element and in the pipes. The element becomes insulated under a crust and heats less well: water arrives at around 85 °C instead of the expected 92 to 96 °C, and the extraction turns flat, sour, with no length on the palate. The pipes narrow, the pump strains and the flow drops. A machine that is never descaled eventually stops building pressure altogether, and the repair then costs more than the maintenance that would have prevented it.
How often should you descale your coffee machine with hard water?
The right frequency depends first on water hardness, then on the number of cups. The benchmarks below apply to a household making 2 to 3 coffees a day:
- Soft water, under 15 °f: every 4 to 6 months.
- Moderately hard water, 15 to 25 °f: every 3 to 4 months.
- Hard water, 25 to 35 °f: every 2 to 3 months.
- Very hard water, over 35 °f: every 1 to 2 months.
At 10 cups a day, halve the interval. If your machine has a cycle counter or a descaling light, follow it rather than the calendar: it counts the water that has actually passed through, which the calendar ignores.
Knowing your water hardness
Hardness is measured in French degrees, written °f: 1 °f equals 10 mg of calcium carbonate per litre. There are three ways to find out: a test strip, sold in pharmacies or appliance stores and read in thirty seconds; the annual analysis published by your local water supplier; or the reading shown by the machine itself, when it offers one during initial setup.
We don't give city-by-city values: without a published analysis we can cite, the test strip remains the only reliable measurement in your home, tap by tap.
Hardness doesn't only decide how often to descale: it also changes the taste of the cup, which is another topic. We cover it separately in which water for coffee: bottled, filtered or tap, with the mineral content to aim for and what each option changes in extraction.
Descale a coffee machine in 6 steps
- Empty and rinse the water tank. Remove the water filter if there is one: it would absorb the descaler and skew the process.
- Prepare the solution. About 20 g of food-grade citric acid per litre of lukewarm water, or the dose stated on a commercial descaler. Don't exceed the dose: stronger doesn't mean more effective.
- Start the descaling cycle. If the machine has one, use it. Otherwise, run the solution through in small amounts, alternating between the coffee outlet and the steam wand to treat both circuits.
- Let it work. Stop halfway and wait 15 to 20 minutes with the tank still full: contact time is what dissolves the deposit, not flow.
- Rinse twice. Empty, fill with clean water and run a full tank through, then a second one. Insufficient rinsing is tasted immediately in the next cup.
- Refit the filter and note the date. Put in a new water filter and write the date down somewhere: that's what keeps the schedule on track over time.
Descaler, citric acid or white vinegar?
Commercial descaler is formulated for coffee machines: ready dosage, anti-corrosion agents, compatibility with aluminium and seals. It's the safe choice, especially on a machine under warranty, where using another product may be held against you in the event of a fault.
Food-grade citric acid does the same job on limescale for a much lower cost, provided you respect the dose and rinse thoroughly. It's a widespread, effective solution on simple machines.
White vinegar, on the other hand, is not recommended by most manufacturers. Over time it attacks seals and flexible parts, and its smell clings to the circuit for several cycles. It's a stopgap, not maintenance.
When descaling isn't enough
Descaling doesn't fix everything. If, after two full cycles and proper rinsing, the flow is still weak or the water lukewarm, look elsewhere: hardened seals to replace, a brew group clogged with coffee oils that needs cleaning separately, a saturated water filter, or a thermoblock that has genuinely failed. Coffee that runs too fast with no crema is more likely a grind or tamping issue than limescale.
Keep in mind: freshly roasted coffee will never make up for a scaled-up machine. Maintenance comes before choosing the beans, not the other way round.
A CLEAN MACHINE, FRESH BEANS
Mexico Altura Organic Coffee
Once the machine is descaled, you can taste the difference: a smooth medium-roast arabica reveals what water at the right temperature can extract.
Frequently asked questions
How often should you descale a coffee machine with very hard water?
Above 35 °f, plan to descale every one to two months for 2 to 3 coffees a day, and even more often if you make more than 10 cups a day.
Can you descale a coffee machine with white vinegar?
It's possible but not recommended by most manufacturers: vinegar attacks seals over time and leaves a stubborn smell. Citric acid or a dedicated descaler are better.
How do I know if my coffee machine needs descaling?
The flow slows, the coffee comes out less hot, the pump gets noisier and a whitish deposit appears in the tank or on the steam wand.
Do you need to descale a filter coffee maker?
Yes. It also heats water and scales up as much as an espresso machine. Same schedule, same products, with equally thorough rinsing in clean water.
Does bottled water mean you don't need to descale?
It spaces out descaling but doesn't eliminate it: most mineral waters still contain calcium and magnesium, which eventually build up.
Benchmarks and sources
- Hardness expressed in French degrees (°f): 1 °f = 10 mg of calcium carbonate per litre. Usual thresholds: soft below 15 °f, hard above 25 °f.
- Frequency of 2 to 3 months with hard water, 4 to 6 months with soft water: intervals commonly given in home coffee machine manuals.
- Reference extraction temperature: 92 to 96 °C, a value that drops when the heating element is scaled up.
- Food-grade citric acid, about 20 g per litre of lukewarm water, with two full rinses in clean water.
- White vinegar not recommended by most manufacturers, because of its effect on seals and flexible parts.
For information only: always refer to your machine's manual, which takes precedence over these general benchmarks, especially under warranty.
Our coffees to rediscover after descaling
Related articles
- Which water for coffee: bottled, filtered or tap?
- Organic coffee: what the label really changes
- Arabica vs robusta: what are the differences?
- Café crème, latte, cappuccino: homemade recipes
In short: descale every 2 to 3 months if your water is hard, every 4 to 6 months if it's soft, adjusting for the number of cups. Citric acid or a dedicated descaler, two rinses, and the date written down: that's what prevents breakdowns.
Our 100% arabica coffees are craft-roasted in France in small batches and delivered anywhere in Morocco in 2 to 5 days. Free delivery from 350 DH, cash on delivery.
