I am making a snack food tray. The main part is cherry that will hold mostly dry things such as crackers. There is a detachable cutting board of small end grain maple blocks that will probably be used with oily or greasy stuff like cheeses and sausages. The designer of the plans suggests butcher block oil as a finish, saying it can be washed with soap and water and also easily reapplied when and if necessary. My thought was a salad bowl finish instead. Isn’t it true that butcher block oil is made with mineral oil that does not dry, so it stays sort of oily to the touch? What do you think — should I use salad bowl bowl finish, butcher block oil or something else? – Jim Hagerty
Tim Inman: Just about any food-safe oil would work for you on this project. Don’t get caught up in the marketing lingo used with the specialty oils, though. Basically, you have a choice between a “drying” oil and a “non-drying” one. The drying oils have additives (natural or artificial) that cause the oils to cross-link or chemically “dry” or harden when exposed to air or moisture. “Tung” oil, for example, is a naturally drying oil. Boiled linseed oil is flaxseed oil that can be made to dry naturally by treating it with heat (hence the term “boiled”) or, as is mostly done in today’s world, it can be made to set or harden by the addition of metallic driers like cobalt. With this addition, they essentially change into a form of varnish after hardening. I don’t want this to be a chemistry lesson or a long answer. But the drying oils may contain some small quantities of undesirable metals for food use, and they do eventually fail in a visible way — either by chipping or by getting gummy.
The other choice is the non-drying type oils. These include mineral oil, olive oil or even raw linseed (flaxseed) oil, among others. Since these oils do not harden, they don’t become varnish and don’t chip or get gummy. They never set, so they are easily re-solubilized by new or fresh toppings. A nice thin salad bowl preparation would be fine. Butcher block oil would be good, too. Some salad bowl finishes contain garlic. That might not be a great add-in for a cheese board – or would it!? One last note: avoid animal fats. You don’t want any oil in the wood that could spoil or go rancid over time. Rapeseed oil (canola) might be another good choice you haven’t considered.