Stilly -

I find walnut oil with the other cooking/salad oils at my local supermarket. It seems a few people like it as a salad oil. You may also find sunflower, pecan, safflower, cottonseed, and bunches of "flavored" oils like taragon, sage, dill, etc., as "salad oils" even at fairly low class markets (like where I shop). Specialty salad oils may also be found at a "health food" shop, but are likely to be much more expensive there. The quantities used for your cutting board generally are small enough that a small bottle will last quite a while, unless you have a really big block.

You may also find "walnut oil finish" materials at a lumber yard or woodworking shop, but these are likely to have added hardening/drying/spreading/penetrating materials that make them questionable for food use. Even if specifically labelled for food use, it's usually assumed that the finish will be aged/hardened before used with food.

Bill D.

I'm not sure I'd consider Tung oil for cutting boards, partly because it does harden really well. Once fully hardedned, you can't "replenish" the surface because additional oil can't penetrate the hardened material. It's generally considered "food safe" once it's fully hardened, but allergic reactions by people who use it as a "finish" and handle it in liquid form are fairly common.

The bacteriostatic properties of oils are most effective while the oil is liquid, or at least soft. Walnut oil hardens, but not rapidly enough to really set up before I'd wash and re-oil (wash fairly often, oil if I remember to do it). Of course any nut oil has the potential for allergic reactions in a few people. If that's a problem, a "real butcher block oil" from one of the fancy cookware shops might be "hypoallergenic" for a family member who has difficulty. These, I think, are usually mineral oil/beeswax, although few that I've seen say more than "secret magic ingredients."

John