What Makes Granite Countertops Turn Color:
Granite countertops appear well to heavy use. With normal use and proper maintenance, they are impervious to heat and heat. But granite is porous. Food and liquids left to sit too long could stain the granite and alter its color, especially if the countertops haven’t been properly sealed.
Kinds of Stains
Nearly any colored liquid or food can stain your granite. Frequent culprits include oil, tea, coffee, and vegetable and fruit juices. Even standing water discolors granite if it is allowed to penetrate, but the effect is temporary.
Water stains vanish on their own after the water evaporates. You can remove true stains with a commercial granite cleaner or by making a poultice to draw out and absorb the material. For petroleum stains, make a paste of dishwashing liquid and flour. Expand the poultice on the stain, then tape plastic wrap over it to keep it moist. Leave the poultice on the stain for 24 hours before removing the plastic and then allowing the paste to dry. Substitute hydrogen peroxide to your dishwashing liquid to take care of non-oil stains.