Butcher blocks and cutting boards need to maintain a finish to keep food and liquids from penetrating into the wood. If the wood gets loaded with food or liquids from food (think blood), it won't be long before all sorts of little nasty things take up residence on your butcher block or cutting boards and make it into your food.

To keep this from happening, the wood should be finished. One way to do this that is safe and easy is to use wax. Get yourself some paraffin wax like the kind used for home canning and melt it in a double boiler over hot water. Once the wax is completely melted and liquefied, brush a generous amount of wax over the wood surface on your butcher block or cutting board. Once the entire surface is coated, let it cool until it is hard. Once the wax hardens, scrape off the excess. Then use a utility iron (not one you plan on using on clothes) to heat up the remaining wax so that it can absorb into the wood.