Cleaning stains from granite

Since granite is somewhat porous even when sealed, it can stain if liquids are spilled on the surface. Always clean a spill as soon as possible because the longer it sits on your granite, marble, or other natural stone surface, the harder it is to remove.

Be sure to blot up spills rather than wiping them, this prevents the liquid from spreading over a larger area. 

Once all excess liquid has been removed, use a pH balanced granite cleaner like Supreme Surface Granite Cleaner & Conditioner to cleanse the area. Other common household cleaners such as bleach wipes, ammonia, vinegar, or citrus-based products will do more damage than good and should be avoided when you are cleaning granite and other natural stones.

Using a poultice to remove stains from granite

If a stain is still visible after cleaning, a poultice may be necessary. A poultice is a chemical powder mixture that extracts the stain by absorbing it out. A poultice should be used only as a last resort because the chemicals could damage your granite countertops over time.

Before making a poultice, it is important to determine what has caused the stain. Different stains require different chemicals. Common stains include oil based stains that come from cooking grease, milk, or cosmetics (these will darken the stone) and organic stains that come from coffee, fruit, tobacco, or animal waste (causing a pinkish-brown stain). If you are unsure what has stained your granite, it is best to consult with a natural stone professional for advice.

Making a poultice

A poultice is made from an absorbent material such as talc, whiting chalk, or molding plaster mixed with a liquid chemical. You can also use white cotton balls, white paper towels, or gauze pads to make a poultice that will remove stains from granite.

For oil based stains, mix the absorbent powder with mineral spirits until you get a paste the consistency of peanut butter (if using paper towel, soak the paper towel in the liquid and let drain until it no longer drips).

For organic stains, follow the same procedure only using 12% hydrogen peroxide in place of mineral spirits.

Don’t ever use more chemicals than you need when cleaning natural stone because harsh and abrasive chemicals can etch and dull the surface.

Applying the poultice

Wet the stained area with distilled water and place the poultice on top of the stain about 1/4-inch thick and overlapping the edges of the stain by about 1 inch. Cover with plastic and tape the edges to create a seal.

Poke several small holes in the plastic so that the poultice can thoroughly dry. It is during the drying process that the chemical in the poultice pulls the stain out of the top levels of granite.

Letting the poultice dry completely is very important, because if it is not left on the stain long enough, it will not work at capacity.

Drying could take between 24 and 48 hours. After the poultice has dried, remove it (with a plastic scraper if necessary) and rinse the area with water. Then go over the area with a good granite cleaner such as Supreme Surface Granite Cleaner & Conditioner.

This process can be repeated three to five times if necessary. If a poultice fails to remove a stain from marble, travertine, or limestone (or makes it worse) it is possible that your natural stone is etched rather than stained. Consult with a natural stone professional for advice.

Preventing granite stains

The best way to handle granite stains is to keep them from happening in the first place. Cleaning granite daily with Supreme Surface Cleaners will help protect your countertops and floors. These cleaners contain a proprietary conditioner called ioSeal that fills the pores in your granite, preventing it from absorbing liquids.