Home woodworkers often craft products that come into contact with food, such as cutting boards, serving bowls, utensils and more. Such products need to be treated with food-safe wood finishes before being used to prepare or serve meals. This guide covers the differences among the best food-safe finishes to use in your kitchen.
What Makes a Finish Food-Safe?
Most finishes give wooden kitchenware a shiny, glossy appearance. Many finishes contain solvents used as bonding agents and should not be consumed directly, but become safe when the solvent has time to evaporate or bond with oxygen molecules.
To be considered truly food safe, a finish must cure properly, which takes much longer than drying. Curing times can vary based on type of finish and your home’s humidity and temperature levels. Curing times will also be affected by how heavily the coat of finish was applied.
Being considered food safe does not mean a finish will work for all types of surfaces that come into contact with food. For example, a finish that forms a film isn’t suitable for cutting boards or utensils used for cooking and serving. A piece of this film could be cut away and accidentally consumed.
Food-Safe Oil Finishes
Oil finishes soak into the porous wood surface. Kitchenware such as a cutting board can get scraped or cut by metal utensils. For items like cutting boards, choose oil finishes instead of film finishes that have a chance of cracking.
- Mineral oil, also known as liquid paraffin and butcher’s block finish, is easy to apply. It has lower water resistance and requires reapplication more frequently. Mineral oil is one of the most common food safe finishes.
- Tung oil is extracted from nuts. Known for good water resistance, it often requires numerous coats. It leaves a natural finish that showcases the grain. Once thoroughly cured, it is food-safe.
- Raw linseed oil, extracted from flax seeds, has a good appearance. However, it has a lower water resistance and a long curing time. The drying time for raw linseed oil could take weeks. Do not use boiled linseed oil. It is considered toxic and not food-safe. Use caution with rags used to apply linseed oil. These oil-soaked rags are a fire hazard and can spontaneously combust. Rags should be dried individually and away from flammable materials and structures.
- Walnut oil, made of pressed walnuts, is available as a salad oil. It is easy to apply, but requires frequent reapplication. Walnut oil is not recommended for those with nut allergies.
Tip: Olive oil or vegetable oil can become rancid if left at room temperature for extended periods. Avoid using them as wood finishes.
Food-Safe Film Finishes
Film finishes leave a coating, or film, on the surface of the wood.
- Shellac, derived from Indian lac bugs, is a common food-safe film finish. It is water-resistant, but can be prone to blushing or water rings. Available in different hues, shellac is sold in liquid form or in flakes that must be dissolved in ethanol before application. The ethanol evaporates during the curing process. Shellac sold at The Home Depot is already dissolved in ethanol.
- Polyurethane protects wood from scratches or damage. It leaves a shiny coat. However, the fumes and long curing time require a well-ventilated area.
Don’t use film finishes on cutting boards. If you cut through the film, pieces of the finish can get into your food.
Food-Safe Wax Finishes
Some kinds of waxes serve as a food-safe finish or add an additional protective topcoat. Wax is typically used as a final coat after finishes such as polyurethane, shellac or tung oil have fully cured. Using wax can revitalize wood finishes. It also helps buff the finish to a more consistent sheen.
- Beeswax is made by honeybees. Added to oil finishes, it makes them more water repellent.
- Carnauba wax is a standalone finish or a topcoat with another finish. It tends to be harder and more water-resistant than beeswax. It is often added to beeswax-based polishes to increase their hardness and sheen. Carnauba needs to be melted to be applied.
Check the manufacturer’s instructions to determine if a wax product is considered food safe. Tinted waxes should not be used on surfaces that come into contact with food. The pigment and other harsh chemicals in tinted waxes can make you sick.
Mixing wax and oil finishes is not recommended. The wax that is added to oil finishes isn’t the same as the wax used for buffing.
Applying a Food-Safe Finish
In general, applying a food-safe finish to unfinished wood tables or kitchenware is a simple process.
- Most items can be sanded with 320-grit sandpaper until smooth. Fully remove all dust.
- When using an oil finish, apply a generous amount to a cloth. Spread until the surface is covered. Let dry for 15 minutes. Apply an additional coat. Use 1 to 2 coats for hardwoods, 3 to 4 coats for softwoods.
- Apply wax with a cloth until the surface is covered. Wipe off excess when finished. Before applying wax, be sure to refer to the manufacturer’s instructions to see if the wax is food-safe. Once you've allowed the wax ro dry, buff it with a clean shoe polish brush or soft cotton cloth.
- Allow newly finished pieces to dry and and then cure fully. Drying is different from curing. While a finish may feel dry to the touch, it may not be fully cured. Allowing finishes to dry for at least 24 hours should provide enough curing time for most. Check the instructions on the product you’re using for specific drying and curing times.
Tip: When sanding, you’ll need to determine how much is right for the piece you plan to finish. For example, if you’re making your own cutting board, you’ll want to start sanding with the lowest grit of sandpaper. Then continue sanding with higher grits until the job is done.
The right food-safe finish will make wood bowls, trays and more both beautiful and functional. Natural oils such as walnut give a rich finish and contain no chemicals. Other finishes, such as varnishes and shellacs, contain chemicals to make them dry quicker. However, once thoroughly cured, these finishes are considered food-safe.
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