How to Remove Stains from Granite
Since natural stone is porous, moisture that pools on it for more than a few minutes—a bit of olive oil under the bottle, an errant coffee spill—can seep in. A sealant will prevent this, but it wears down over time. "If you notice that short-term contact with water darkens your stone, that's the best indicator that you need to reseal," says Mark Meriaux, technical manager at the Natural Stone Institute, in Oberlin, Ohio. To keep your surface in the best shape until resealing is possible, continue reading—here's a strategy for removing even deep-set discolorations in the meantime.
Clean the Area
For an oil stain, wipe with grease-lifting dishwashing soap, such as Dawn ($4.99, target.com). For other types (think food, coffee, tea), grab a hydrogen-peroxide-based cleaning spray, like Lysol with Hydrogen Peroxide: Oxygen Splash ($2.76, walmart.com). Though gentler "safe-for-stone" options are ideal for regular cleaning, this works best on dark marks—so use this tougher approach as needed.
Mix a poultice paste of baking soda and water (for oil-based stains), or baking soda and peroxide (for others), until it's as thick as peanut butter. Spread the mixture over the spot, cover it with plastic wrap that you've poked a few holes in, and secure it with masking tape. Let the poultice paste stand for 24 hours.
Remove and Buff
Pull off the plastic, and clear the white residue with a wooden or plastic scraper. Then rinse the surface with distilled water and polish the stone with a cloth.