How to clean granite countertops without damaging the seal

Step by step: how to clean granite countertops without damaging the seal

Safety first. Most penetrating sealers contain solvents: open windows, wear gloves and follow the label. Never mix bleach with ammonia or vinegar when disinfecting nearby surfaces, and keep acidic cleaners off the stone.

1. 1

   Clear crumbs and scrape stuck food

   Brush crumbs off with a dry cloth so they do not scratch the sealer when you wipe. Lift dried food or dough with a plastic scraper or an old credit card held flat.

2. 2

   Spray a pH-neutral stone cleaner

   Mist a section with a stone cleaner labeled pH neutral or safe for granite. If you use soap and water instead, use only a drop or two of mild dish soap in a quart of warm water, since extra soap leaves a dull film.

3. 3

   Wipe with a damp microfiber cloth

   Wipe in overlapping strokes from the back of the counter to the front. Rinse the cloth often. If you used soap, go over the counter once more with a cloth dampened in plain water.

4. 4

   Buff the counter dry

   Dry and buff with a second clean microfiber cloth. Water left around the faucet and sink edge dries into white mineral rings, so pay attention there.

5. 5

   Make a poultice for oil or coffee stains

   For a dark oil stain, mix baking soda and water into a paste as thick as peanut butter. For coffee, tea or wine stains on light granite, mix baking soda with 3% hydrogen peroxide instead. Spread it 1/4 inch thick over the stain and slightly past its edges.

6. 6

   Cover the poultice and let it work

   Cover the paste with plastic wrap, tape down the edges, and poke a few small holes in it. Leave it 24 to 48 hours as it dries and draws the stain up out of the stone, then scrape it off and rinse. Repeat if the stain has faded but not gone.

7. 7

   Test the seal with water

   Every 6 to 12 months, put a few spoonfuls of water on the busiest areas, near the sink and stove, and wait 10 to 20 minutes. If the stone darkens under the water, it is absorbing and needs resealing.

8. 8

   Reseal when the test fails

   Clean the counter, let it dry for 24 hours, then apply a penetrating granite sealer following the label, usually leaving it for a few minutes and wiping off all excess. Avoid using the counter until the sealer cures.

What not to use on granite countertops

The best way to clean granite countertops is the gentle routine above, every day. Do not use vinegar, lemon, Windex with ammonia, bleach or abrasive powders. The Natural Stone Institute warns that acids such as vinegar can etch stone and wear down sealers, and recommends pH-neutral cleaners and non-abrasive tools.

That last point comes from the Bar Keepers Friend FAQ, which says its standard cleansers are too acidic for marble and polished stone.

How often should you seal granite countertops?

Seal granite when the water test shows it absorbing, which for many kitchens is every one to three years. Some dense, dark granites barely absorb anything and rarely need sealer.

The Natural Stone Institute’s granite care advice describes the water test: put a little hot water on the stone, wait 10 to 20 minutes, and wipe it off. If the spot darkens, it is time to reseal with a penetrating sealer. The same article recommends a neutral stone cleaner for daily wiping and warns that dish detergent can leave a residue that dulls the surface.

• Test near the sink and stove first; those areas wear fastest.
• Use a penetrating (impregnating) sealer made for stone, not a topical coating that sits on top.
• Wipe off all excess sealer before it dries, or it leaves a hazy film.

Stain or etch: what is that spot on your granite?

A dark spot is usually a stain soaked into the stone; a dull, lighter spot is usually etching or a worn sealer. They need different fixes.

• Dark, spreading spot (oil, butter): baking soda and water poultice.
• Brown or pink spot (coffee, tea, wine): baking soda and hydrogen peroxide poultice on light stone; test on dark stone first.
• White ring by the faucet: hard water. Wipe with stone cleaner and dry the area daily.
• Dull, rough patch where lemon or vinegar sat: etching. Granite rarely etches, but some stones sold as granite contain calcite. A stone restoration pro can polish it out.

For quartz counters, which need no sealer, see how to clean quartz countertops. For quartzite, see how to clean quartzite countertops.

Mistakes to avoid

• Cleaning with vinegar or a citrus spray because it is natural, which wears away the sealer.
• Using a lot of dish soap and leaving a streaky film that dulls the stone.
• Leaving oil bottles or wet sponges sitting on the counter, which leaves rings.
• Resealing on a schedule without testing, so the sealer builds up into a haze.
• Scrubbing a dull spot with abrasive powder, which makes etching worse.