How to Clean and Seal Granite Countertops: A Boston Fabricator’s Guide

Granite is one of the most durable countertop surfaces you can put in a kitchen — but “durable” doesn’t mean “maintenance-free.” A few simple habits keep granite looking new for decades. Here’s how we tell our Greater Boston customers to clean, test, and seal their granite countertops.

Cleaning granite the right way

For everyday cleaning you don’t need anything fancy. Warm water, a few drops of dish soap, and a soft microfiber cloth handle the vast majority of messes. Wipe spills as they happen, dry the surface afterward, and that’s it.

What to avoid:

• Acidic cleaners — vinegar, lemon, bleach, and many “all-purpose” sprays slowly degrade the sealer and can dull the polish.
• Abrasive pads or scouring powders, which leave fine scratches.
• Leaving oil, wine, or coffee to sit — granite is stone, and standing liquids can soak in if the seal has worn thin.

For a deeper clean, a granite-safe pH-neutral stone cleaner is a worthwhile investment.

Does your granite need sealing? The water test

Most granite is sealed at fabrication, and that seal wears down over time — but not on a fixed schedule. Instead of guessing, run the water test: pour a tablespoon of water onto the counter and wait about 15 minutes.

• Water beads up and stays on top — your seal is fine, no action needed.
• Water soaks in and darkens the stone — it’s time to re-seal.

Dense granites (and most quartzites) may go years between sealings; lighter, more porous stones may need it closer to once a year.

How to seal granite countertops

Sealing is a 20-minute job most homeowners can do themselves:

1. Clean the surface and let it dry completely — several hours, or overnight.
2. Apply an impregnating stone sealer evenly with a clean cloth.
3. Let it sit per the product instructions — usually 5–15 minutes — so it penetrates.
4. Wipe off all excess before it dries, or it can leave a hazy film.
5. Let it cure (often 24 hours) before heavy use.

Re-run the water test afterward to confirm the seal took.

Lifting stains

For an oil-based stain (grease, butter), a poultice — a paste of baking soda and water left under plastic wrap overnight — draws the oil back out. The same approach usually works on water-based stains. Avoid scrubbing with anything abrasive.

Granite rewards a little routine care with decades of service. Clean it gently, test the seal once or twice a year, and re-seal when the water stops beading. Questions about your specific stone? The team at Pablo Marble and Granite, LLC is happy to help — we’ve installed granite in hundreds of Greater Boston kitchens.