Maintaining polished concrete countertops isn't difficult but it is necessary to retain their beauty and to give them a long life. A few simple steps of routine maintenance will achieve this.
Step 1 - Sealing and Coating
If you have new countertops you will notice small holes that have a sponge-like appearance. This is because concrete is porous. You need to fill these holes with a penetrating sealer to help seal the concrete surface. Concrete countertops can get stained with both acid and grease and sealing them will help prevent this. They should be sealed annually with a penetrating sealer then waxed once a month for added protection.
After they are sealed, you can use a concrete coating sealer for shine. These come in liquid and paste varieties and are applied just like car wax and then buffed to a shine. It will also protect from stains and scratches but not make the countertops impervious.
Step 2 - Regular Cleaning
As with any household surface, regular cleaning is the key to a long life. Dishwashing liquid on a sponge with warm water is generally all you will need to clean them. While cleaning always watch for hairline cracks that can allow water to penetrate. Use the penetrating sealer to seal them.