I treat the finished boards with walnut oil, and then with a mixture of walnut oil and beeswax. The oil fills the wood pores and repels food particles, and liquids. The addition of beeswax provides a more durable finish. It renders the wood more water resistant and reduces wear and tear.
Clean the board with warm soapy water. Do not place the board in the dishwasher. With usage the board will lose some of its luster. To restore some of the initial shine and feel, apply a coat of edible oil to the board, allow it to soak in, and then wipe dry. It is not advisable to use vegetable or cooking oils as eventually the wood will attain a rancid odor. A walnut or almond oil is an acceptable product and is available in most grocery stores. USP (United States Pharmacopeia)-grade mineral oils are other popular choices.
A beeswax top coat is an optional addition to the re-finishing process, It helps to keep moisture and other contaminants from getting into the wood surface. Simply wipe it on with a clean cloth. Once the finish has had some time to dry it can be buffed to a shine.
For boards that have been exposed to extensive cutting, it may be necessary to re-sand the surface, and then re-finish with oil and beeswax.