How to Clean Granite (Countertops, Sinks) — Naturally and Without Damage

Granite: the kitchen's marble, but more forgiving

Granite is the most common natural stone in kitchen worktops and bathroom basins for one reason: it's made mainly of quartz and feldspar — hard silicates — not calcite like marble. That means it resists acids and scratches better, and many mistakes that would do permanent damage on marble stop at the sealer on granite. "More tolerant" doesn't mean "indestructible", though: granite has its weak points, and knowing them is the difference between a worktop that stays beautiful for twenty years and one that gets marked within three.

Routine cleaning: neutral soap is (almost) always enough

Disinfection: alcohol and hydrogen peroxide

To sanitise a granite worktop after cutting raw chicken or during flu season, there are two low-risk options. 70% alcohol — denatured alcohol from the pharmacy or large supermarkets at CHF 5–8/L — sprayed and left to evaporate for 30–60 seconds is the cleanest choice: effective, safe on sealed granite, leaves no residue. 3% hydrogen peroxide (CHF 3–5 at the pharmacy) works against bacteria but used often can lighten the sealer, so it should be alternated sparingly.

Pure bleach on granite is always to be avoided: it discolours the sealer and stiffens the micro-fissures, opening the door to future stains.

Stubborn stains: the DIY poultice

Sealing: the secret of longevity

Granite has natural micropores invisible to the naked eye that are the surface's weak point. Without an active sealer, these pores absorb oil, wine and coffee in minutes; with an active sealer, the same liquids stay on the surface for 10–30 minutes before starting to absorb, giving you the time to intervene. The sealer needs renewing every 1–3 years depending on use and granite type.

The sealing test

The test takes five minutes: pour a few drops of water onto the granite, wait five minutes, and observe. If the drops are still on the surface, the sealer is active and all is well. If the water has been absorbed and the granite looks darker locally where the drop sat, it's time to re-seal.

How to apply the sealer

The recommended products are Akemi Stone Impregnator, Bellinzoni Idrorep and Tenax Hydrex, sold at CHF 30–60/L for quantities sufficient for 10–15 m² of surface. The procedure starts with a deep clean using neutral soap, rinsing, full drying and twenty-four hours of waiting so the granite is dry through and through. Apply with cloth or brush in an even layer, leave for 10–15 minutes of absorption, remove the excess with a dry cloth, and wait twenty-four hours before putting the surface back into use. The wrong product here is the one applied in haste on a not-perfectly-dry surface — the result is uneven sealing that needs reapplication.

Mistakes to avoid

When you need a professional

Engineered quartz (Caesarstone, Silestone): a more tolerant cousin

Not to be confused with natural granite: engineered quartz worktops are 95% quartz bound in resin, and the most important practical difference is that they're non-porous. That means they don't need sealing, ever. Cleaning is the same as granite — neutral soap, microfibre — with two additional cautions: never pure vinegar, because it can stain the resin, and never pans straight from the oven placed directly, because resin melts above 150 °C. For the rest, they're very easy surfaces to manage — often chosen precisely for that.