A wax wood conditioner or food grade mineral oil should be applied to the board once a month (might be more or less depending on the number of times the board is used). If the wood looks dry then give it some oil. Oil and wax will fill the wood pores on the surface and help to prevent water and bacteria from becoming trapped in the board. We use our own blend of 100% food safe beeswax, carnauba wax, mineral oil, orange oil, lemon oil, and vitamin E on our boards prior to shipping.   Don’t use vegetable oils to seal your board because the oil will become rancid over time. Coat the board in oil and allow it to soak in for about 15 minutes and them wipe off the excess oil. If the oil absorbs very quickly then you need to apply a second coat. Don’t allow the board to dry out.