Musing: food-safe finishes for your hand-crafted wooden utensils and other kitchen items
I have a PhD in Chemistry and am a student of historical finishing technologies. I’ve also been a woodworker and woodcarver for nearly 50 years and have made a lot of kitchen items and utensils in wood. Centuries of trial and error provided suitable finishes to our woodworking ancestors. In the last 100 years an explosion of new finishing technologies has occurred and many of these finishes are not food-safe. Manufacturers don’t always clearly label their products as not being food-same, leaving woodworkers ill informed. This blog post is not to tell you what finish to use on your wooden wares—that is your decision—I simply want to arm you with the knowledge you need to make safe decisions so that you don’t make your family, friends, and customers sick or worse.
When choosing a finish for eating utensils, there are three key health considerations:
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Is the material food-safe?
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Does the material turn rancid after application?
- Does it contain allergens?
If your finish meets these two requirements, the choice largely comes down to personal preference regarding aesthetics, application, and durability.
FOOD SAFETY
Many oils and finishes contain additives to provide UV protection, improve durability, and speed up drying and polymerization. Many of these additives are not food-safe, so it’s crucial to read product labels and verify the absence of harmful chemicals. This is a common issue with many commercial oils like Tung oil and Linseed oil. If these oils are pure, they are safe; however, commercial versions often contain additives. For example, boiled linseed oil typically contains additives, while raw linseed oil usually does not and is safe for food contact. Read the product label and if it does not explicitly state that the finish is food-safe, I recommend not using it.
AVOIDING RANCIDITY
Some oils harden (polymerize) when exposed to air, forming a stable film. These are referred to as “drying oils”. Some popular drying oils are:
- Walnut Oil
- Raw Linseed Oil
- Pure Tung Oil
- Safflower Oil
- Poppyseed Oil
These oils provide a durable, food-safe finish, although some take longer to harden, which is why additives are sometimes used to speed up the process, making them unsafe for food contact. Many commercial Tung oil and Linseed oils have additives and are not food-safe. Check their labels.
Other materials such as beeswax, carnauba wax, fractionated coconut oil, and mineral oil (provided they contain no additives) are also good food-safe finishes (note that unfractionated Coconut oil does go rancid). However, these finishes are not as durable and require more frequent reapplication because they don’t polymerize and harden like drying oils.
ALLERGENS
Finally, keep in mind some some people have allergies to certain foods, oils, and chemicals and this might influence your choice for a finishing material. For example, Walnut oil is an excellent drying oil but it is estimated that 0.5% to 1.0% of the U.S. population has a tree nut allergy (note that walnut allergy is a very small fraction of this estimated range but is still an important consideration).
By ensuring that the oil or finish you choose is food-safe, non-rancid, and non-allergenic, you can safely maintain your wooden eating utensils.
One Comment
a hack of all trades
A spoon carver on a Facebook sppon carving group asked me about grapeseed oil and hemp seed oil – a very good question! Here’s my reply:
Grapeseed oil is used widely in the food industry and kitchen. It is a high temperature oil used for high temperature frying because it has a very high smoke point (425°F) and has a mild flavor. I use it to season my cast iron cookware. As a wood finish it is sometimes used in applications similar to mineral oil. It is a non-hardening oil and it can go rancid (although relatively slowly) and soaks into the wood. Some people use it to oil wood cutting boards and utensils but these should be cleaned in water and treated regularly to minimize the oil turning rancid.
Hemp Seed Oil. Ok, let’s be VERY clear about the use of the work “hemp”. Hemp oil and hemp seed oil are two very different products so don’t make the mistake of using hemp oil when you intended to use hemp seed oil. To. make matters worse, companies in the finish industry frequently use “hemp oil” instead of the correct “hemp seed oil” which can be confusing.
Hemp oil, also called CBD Oil, is not derived from the seed of the hemp plant. It is used to treat anxieties and reduce pain. It is NOT recommended as a finish because it contains CBD, one of the two active ingredients in pot.
Hemp seed oil is produced from the seeds of the hemp plant, is food-safe, and used in cooking. It has a nutty flavor akin to walnut oil and typically very little or no CBD. It is classified as “low allergy”. It is a drying oil and is used on wood items that contact food like utensils and cutting boards. It does not require a solvent like Tung Oil does. It is similar to linseed oil in that it imparts a rich, deep color to most woods. Just make sure that it is pure hemp SEED oil and it should be fine.