Descaling protocols and risks
How descaling works in espresso machines, when to apply it, and the potential risks if done incorrectly.
- Coffee Basics Nerds
- 2 min read
Article 8 of 12 in Espresso Machine Technology/
What is Descaling?
- Definition: The chemical removal of limescale (calcium and magnesium carbonate deposits) from boilers, pipes, and valves.
- Why Needed: Scale reduces heat transfer efficiency, clogs passages, and can damage machine components.
Descaling Protocols
- Chemicals Used: Citric acid, sulfamic acid, or manufacturer-approved solutions.
- Procedure (General):
- Power down and cool machine.
- Drain water from boiler.
- Fill with descaling solution.
- Heat and circulate through water path.
- Rinse thoroughly with fresh water multiple times.
- Frequency: Depends on water hardness and filtration—typically every 6–12 months for unfiltered water, or much less with proper water treatment.
Risks of Descaling
- Seal & Gasket Damage: Strong acids can degrade rubber and silicone.
- Metal Corrosion: Overuse or high concentration may pit brass, copper, or stainless steel.
- Residue Risk: Incomplete rinsing leaves chemical taste and health hazards.
- Component Loosening: Large flakes of scale can break free, clogging valves and solenoids.
Alternatives & Prevention
- Use proper water filtration and conditioning to minimize scale buildup.
- Prioritize prevention (softeners, RO with remineralization) over frequent descaling.
- Some manufacturers advise against DIY descaling, recommending professional service.
Best Practices
- Always follow manufacturer guidelines.
- Use approved descaling solutions in correct dilution.
- Rinse extensively to remove all chemical traces.
- Consider professional servicing for commercial machines.
Summary
Descaling is an essential but risky maintenance procedure. Correct protocols safely remove scale, but improper descaling can damage seals, metals, and flavor quality. Prevention through water management and professional servicing is the safest long-term strategy.