How to Descaling Your Espresso Machine— PEDROCCHI S60
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What Limescale Actually Is
All tap water contains dissolved minerals, mainly calcium (Ca²⁺) and magnesium (Mg²⁺). These ions are invisible and harmless in cold water.
When water is heated inside your S60 boiler — especially above 60°C / 140°F — dissolved bicarbonate minerals break down and recombine into solid crystals. The main one is calcium carbonate (CaCO₃), the same compound found in chalk, limestone, and seashells. Magnesium salts deposit in a similar way.
These crystals don’t stay suspended. They attach to hot metal surfaces: boiler walls, heating elements, water pipes, the group head, and solenoid valves. Over time, the layer thickens.
Hard water (high mineral content) deposits scale faster. Soft water deposits more slowly, but it doesn’t eliminate the problem. If your water supply is above 120 ppm hardness, your S60 will scale — the only question is how quickly.
Why does location matter? Scale forms fastest where water is hottest and flow is slowest. That’s why the boiler and group head are usually the first components affected.
The Chemistry of Descaling (The Core)
Here’s the fundamental reaction, simplified:
Acid + Carbonate → Soluble Salt + CO₂ + Water
In practice: when you introduce a descaling acid to calcium carbonate, the acid dissolves the solid scale and converts it into a water-soluble compound that can be flushed away. Carbon dioxide is released as bubbles — that fizzing you see is the reaction working.
Common descaling acids:
| Acid Type | How It Works | Notes |
|---|---|---|
| Citric acid | Mild, food-safe, slow-acting | Good for light scale; can leave sticky residue if not rinsed thoroughly |
| Sulfamic acid | Stronger, faster | Common in commercial descalers; effective on heavy scale |
| Phosphoric acid | Fast, effective | Often buffered in proprietary formulas |
| Lactic / formic acid blends | Moderate strength, low odor | Found in many OEM-approved descalers |
What about chelating agents? Ingredients like EDTA or gluconate don’t “burn” through scale — they grab onto calcium and magnesium ions and hold them in solution, preventing them from re-depositing. Think of them as chemical escorts: they bind the minerals and carry them out during flushing.
Why commercial descalers are blends: A pure acid alone can be aggressive to metal and seals. Commercial formulas combine:
Acid — to dissolve scale
Surfactant — to help the liquid penetrate and wet surfaces
Corrosion inhibitor — to protect stainless steel, brass, and seals
This is why “just use vinegar” is not equivalent. Vinegar (acetic acid) works, but it lacks the protective components and leaves a strong odor that can linger in your machine.
Choosing a Descaler for Your S60
Your S60 contains multiple materials:
Stainless steel (boiler, some fittings) — generally acid-resistant, but can pit under prolonged exposure to strong acids
Brass (valves, fittings) — more sensitive to acidic attack
Silicone seals and gaskets — can swell or degrade with repeated acid exposure
Aluminum components (if present) — highly reactive to acid; avoid strong acids
Why household vinegar is risky: Acetic acid is weak, but it’s also volatile and smelly. It can leave residual taste in the water path and doesn’t contain corrosion inhibitors. Repeated use may accelerate seal wear.
Why pure citric acid isn’t ideal either: It’s effective, but without a surfactant it penetrates scale more slowly, and without an inhibitor it offers no metal protection. It also tends to leave a sticky film if not thoroughly flushed.
Best practice: Use a descaler approved by PEDROCCHI or specifically formulated for espresso machines. These are designed for the exact material mix in your S60 — stainless steel, brass, and food-grade silicone. If you can’t get OEM, choose a commercial espresso descaler with a clear material compatibility statement.
Key Variables That Control the Reaction
Descaling isn’t just “pour in and wait.” Four variables determine success:
Concentration — Too weak: slow, incomplete. Too strong: risk to seals and metal. Follow the descaler’s instructions.
Temperature — Warm solutions react faster. But never boil or use hot water unless the descaler explicitly allows it. Heat accelerates both descaling and corrosion.
Contact time — Scale doesn’t dissolve instantly. Let the solution sit in the boiler and water path long enough to work.
Cycles — One pass is rarely enough. The most effective method is react → pause → rinse, repeated several times. This lets fresh solution reach new surfaces and prevents saturated solution from re-depositing minerals.
Rinsing and Neutralization
No matter which descaler you use, what really determines safety and flavor is the rinsing and neutralization after descaling. The machine’s water path will be full of acidic residue and dissolved minerals, and you must flush it out completely.
Why multiple rinses are necessary: A single rinse dilutes the residue but doesn’t eliminate it. Acid trapped in valves, seals, and narrow tubes will slowly leach into your next shots. You need enough fresh water cycles to bring the pH back to neutral and clear all dissolved solids.
How to know you’re done:
The rinse water runs clear with no bubbles or fizzing
No acidic smell or taste in the water
The machine’s built-in rinse cycle (if available) completes without warnings
Residual descaler affects:
Flavor — acidic or chemical taste in espresso
Seals — prolonged acid contact degrades silicone and rubber
Metal — brass and aluminum are especially vulnerable
If in doubt, run one more rinse cycle. It costs nothing but water.
S60 Descaling Steps
Always follow your machine’s manual and on-screen prompts. Button names may vary slightly between firmware versions.
Step 1: Fill the water tank, preferably with purified water.
Step 2: Wait for the machine to warm up.
Step 3: The display stops flashing, indicating warm-up is complete.
Step 4: Turn the function knob to the descale position, and open the steam switch at the same time.
Step 5: Press the Manual button to start descaling.
If you still cannot complete descaling, we recommend adding a specialty coffee cleaning powder, such as URNEX brand cleaning powder.
Frequency and Warning Signs
How often should you descale?
| Water Hardness | Daily Use (1–3 shots) | Heavy Use (5+ shots) |
|---|---|---|
| Soft (< 60 ppm) | Every 3–4 months | Every 2–3 months |
| Medium (60–120 ppm) | Every 2–3 months | Every 4–6 weeks |
| Hard (120–180 ppm) | Every 4–6 weeks | Every 3–4 weeks |
| Very hard (> 180 ppm) | Every 3–4 weeks | Every 2 weeks |
Signs your S60 needs descaling now:
The descale indicator light stays on continuously
Water flow from the group head is slower than usual
The steam wand produces weak or irregular steam
Brew temperature seems lower than set
You see white chalky deposits around the group head or steam wand tip
Don’t wait for a complete blockage. Scale reduces performance gradually — descaling early is easier and safer than descaling late.
Cleaning ≠ Descaling
These are two different problems with two different solutions. Confusing them leads to ineffective maintenance.
Coffee-side cleaning (oils, grounds, residue):
Group head — wipe and backflush regularly (C2/C3 cycles where applicable)
Portafilter basket — soak in espresso detergent (A12)
Portafilter handle — wipe clean, avoid harsh chemicals (A10)
Drip tray and grounds bin — wash with mild soap (B8, B4)
Bean hopper and grinder burrs — clean regularly to prevent rancid oil buildup
Water-side descaling (mineral scale):
Boiler, water pipes, group head water path, steam wand interior
The one-sentence distinction: Scale is a water-side chemical problem. Coffee oil residue is a coffee-side cleaning problem. You need both — but they require different products and different procedures.
Safety Notes
Ventilate the area. Descaling solutions can release fumes, especially in small kitchens.
Never mix descalers. Combining different acid products can create dangerous reactions or damage your machine.
Never disassemble a hot machine. Let it cool completely before removing any fittings.
Wear gloves if you have sensitive skin. Descaling acids can irritate.
Check material compatibility before using any descaler — especially if your S60 has aftermarket fittings or modifications.
Keep descaler away from children and pets.
FAQ
Can I use vinegar to descale my S60?
You can, but it’s not recommended. Vinegar is a weak acid that works slowly and leaves a strong odor. It lacks corrosion inhibitors and surfactants, so it’s less effective and potentially harsher on seals over repeated use. Use a proper espresso descaler instead.
What’s the difference between citric acid and commercial descaler?
Citric acid is a single-ingredient acid. Commercial descalers add surfactants (for penetration) and corrosion inhibitors (for metal protection). The blend is safer for your machine’s internal materials and usually more effective.
How often should I descale?
Depends on your water hardness and usage. See the table above. As a rule: if you notice slower flow or taste changes, descale sooner.
Can I drink the first espresso after descaling?
No. Run at least 2–3 full rinse cycles (or follow the machine’s rinse program) until the water runs clear and neutral-tasting. The first shot after rinsing should be discarded as a precaution. The second or third shot is safe.
Will descaling void my warranty?
Using a non-approved descaler or failing to follow the manual’s procedure may affect warranty coverage. Always use a PEDROCCHI-approved or espresso-specific descaler and follow the documented process.
Ready to Protect Your S60?
Limescale is inevitable — but damage isn’t. With the right descaler and a proper routine, you can keep your PEDROCCHI S60 running at peak performance for years.