How to Remove Stains from Kitchen Countertops
The best way to get rid of spots on kitchen surfaces
"Stones are basically sponges," says Fred M. Hueston, director of the National Training Center for Stone and Masonry Trades, in Longwood, Florida. He's working in a kitchen, mixing up an odd-smelling poultice of flour and hydrogen peroxide in the hope of removing a stubborn coffee stain from an island countertop. Spread over the stain, the paste should literally pull the discoloration out of the red travertine. "Granite, marble, and limestone consist of interlocking mineral crystals with pores between them," he explains. "So spills soak into unprotected stone in just 15 to 20 minutes for granite, and 30 minutes to an hour for marble and limestone." The liquid evaporates, but a mark remains.
Hueston, who literally wrote the book on the subject of stone restoration (Stain Removal Guide: For Stone, Tile, and Concrete), will leave the poultice in place for 24 hours. This will allow it to "wick" the stain out of the countertop, in the same way that poultices made with other ingredients pull oil stains out of concrete or venom out of snakebite victims. He determines his recipe on the basis of the stain and stone types: an absorbent base like dry clay, flour, or a paper towel, and a wicking chemical such as detergent, bleach, or hydrogen peroxide. If the countertop has been both stained and etched, the stone must be polished and a new sealer applied. "Cleaning spills right away and using coasters is a lot easier," he says.
Preparing the poultice
Fred Hueston mixes flour and hydrogen peroxide to create a poultice that's about the consistency of creamy peanut butter. Peroxide works best for food stains, but in the case of cooking-oil stains, Hueston uses dishwashing liquid, which breaks up the oil. For biological stains — mold, mildew, fungus — he uses household bleach. (The chlorine doesn't bleach the stone, only the stain.) Rust disappears with sodium hydrosulfate, available in over-the-counter rust removers. "I've seen stains go from light yellow to deep purple with the wrong chemical," says Hueston. He always tests the poultice on an inconspicuous spot on the countertop before applying it to the stain.