cleaning sponge dipped in mild soap and water can be used to gently scrub a granite countertop, then it should be rinsed with water and dried with a soft cloth. There are some substances that should always be kept away from granite slabs, such as acidic liquids from natural citrus fruits. Lemon juice, vinegar and strong wine can leave unwanted color stains on a granite countertop, especially light colored countertops. If a recipe calls for use of these acidic liquids during food preparation, just remember to wipe down the granite countertop quickly with mild soap and water.
Fresh meat should also be kept away from a granite countertop, because it can leave blood stains or an unpleasant odor that will stick in your countertop. This can happen even if it has been properly sealed, so home cooks should place a protective material like tin foil, plastic or parchment paper under the meat. This will help absorb some of the water and blood that seeps out of the meat, so as long as the countertop is wiped down afterward it should be safe.
Spilling oil can also damage a granite countertop; in fact, oil is the one liquid that stains granite countertops the most. Cooking oil seeps between tiny pores in the granite surface and stains it from the inside out. This can be prevented by having granite countertops sealed on a regular basis, and by careful food preparation.
Granite countertops are very durable and do resist most stains, but every surface has its natural enemies. Avoiding abrasive cleaners, fresh meats, acidic liquids and oils should help avoid most granite stains. Having kitchen countertops sealed at least once a year is the best way to avoid stains, which is one reason why this material is a bit more high-maintenance than other counter materials. The extra work is well worth the beauty it achieves, though.