Cooks and cleaning experts are divided on whether wood cutting boards can go in a dishwasher. Some maintain that these should never be cleaned in a dishwasher, while others say that it's the safest way to disinfect them. The decision of whether or not to put a wood cutting board in the dishwasher depends on the amount of concern about bacteria and the type and quality of the board.
A cutting board that is warped or won't lay flat against the counter is difficult to use. This is one reason many manufacturers and experts warn against washing a wood cutting board in the dishwasher. The heat and water will cause some boards to twist, bend or shrink. Not every board will warp in the dishwasher, however, since it depends on the type, thickness, quality and age of the wood.
In general, thick solid-wood cutting boards will not warp in the dishwasher, while thin laminate boards will, but there is no guarantee or way of knowing whether a board will warp without running it through a dish washing cycle.
Unlike plastic cutting boards, wooden cutting boards can last for years. They do, however, require some special care. Most of the care involves keeping the proper amount of moisture in the wood. Cleaning a wood board in the dishwasher can first oversaturate and then dry out the cutting board.
Even if there is no immediate damage such as warping, continuous dishwasher cycles may eventually cause even heavy-duty hardwood boards to crack or split, reducing the lifespan. The process may take years or could happen within a few washes, depending on the quality of the board. Some damage can be prevented or slowed down with regular oiling.
The best way to sanitize cutting boards, including wood ones, is to clean them in the dishwasher. Spraying the surface with bleach and washing with hot water is not as effective as a full cycle in the dishwasher at high temperatures. Some cooks find it worth the extra assurance that bacteria is killed and the board thoroughly sanitized, to shorten its useful lifespan by cleaning it in the dishwasher.
Specialty and Soft Woods
Cutting boards made from specialty woods, such as bamboo, should not be cleaned in a dishwasher since these woods are sure to warp. The same is true for boards made from soft woods, such as pine. Most boards made from specialty woods will be marked by the manufacturer. Soft-wood cutting boards are usually less expensive, thinner and made up of strips of wood rather than one solid piece.