Can I re-season my knife handles and cutting boards?

**This answer was submitted by a long time Cook'n user and friend - David Jackson, a Chef and woodworker – I believe you will find what he has to say very beneficial. Thanks David!!

You don’t “re-season” wood. It can only happen once. “Seasoning” wood is the process in which the wood dries and cures after being cut. The water dries out and the sap metabolizes, making it possible for the wood to be milled efficiently.

Putting knives in the dishwasher often erodes their finish, which is usually varnish. There are all sorts of “snake oil” products on the market claiming to be “non-toxic” and are labeled such calming names as “salad bowl finish,” etc., but that is a ruse. Oils plasticize over time, and become non-toxic. When varnish cures, the solvents that make it toxic evaporate, making it also non-toxic. Oils add richness of color and contrast to the wood, but do almost nothing to protect it. Varnish creates a nice hard shell if properly applied, which is similar to lacquer; apply a thin coat, let it completely dry for a day or two (it’s only a few hours for lacquer), scuff it a bit with some very fine sandpaper and apply another coat. Repeat until you have the desired appearance and thickness. I prefer sponge brushes to bristle brushes for knife-handles because it’s easier to load them with only a little varnish and holding the brush at a shallow angle also tends to wipe off the excess as you apply.

If knives have highly-figured handles, like birch, figured maple, or some walnut species, I like to apply 3-4 coats of tung oil, allowing a week or two in between coats for each to cure, followed by a coat or two of varnish. It takes the knife out of commission for a while, but it is so worth it when you see the result.

Cutting boards are a different animal. They don’t get varnish. They are oil-treated, if they are treated at all. If the top of a cutting board has been scarred up, simply sanding it down until the scratches are gone (in successive grits, 40, 80, 120, 220) will do quite nicely, as long as the board remains flat (low spots will cause food to not be cut through during processing. However, BUYING a good cutting board, properly constructed, is far more important than knowing how to restore one.

Cheap cutting boards expose the edge-grain, not the end-grain, to the cutting surface. Think of the surface has a bundle of broom-straw or drinking straws. If you cut across, it severs the fiber, and frays, and if you cut along the grain, it leaves a cut where the fibers are separated, but does not fray. Either way, the board is defaced; it’s only a question of severity. However, if the end-grain is exposed, knife blades and even a cleaver will separate the fibers momentarily and they will the return to their original position, unless you are using a serrated blade like a steak knife that has saw teeth and removes some of the fiber (so DON’T DO THAT!). And buyer beware, there are a LOT of products advertised as “butcher block” boards or tops that are merely thick boards that turn the edge-grain up, not the end-grain. If you see stripes on the cutting surface that run the length of the board, it’s edge-grain. If you see squares or rectangles where the wood was cut and glued, and see curved lines that look like arcs from concentric circles (like the top of a freshly sawn tree trunk where you can see the growth rings), you are looking at end-grain.

And again, “common knowledge” regarding the safety of wooden cutting boards and handles is entirely backwards; wood sucks bacteria into its grain and kills it within 60 seconds, even in 125-year old antique cutting boards (this was confirmed in a legitimate lab test) while plastic is harbors bacteria and does nothing to kill it. So stick with wood products if you’re concerned about “cross-contamination,” and try to avoid use (and especially over-use) of antacids, as stomach acid is part of the immune system, as it kills most pathogens as they enter the stomach, and neutralizing stomach acid makes you susceptible to food-borne bacteria.

Also note that bamboo, while very hard and durable, also contains a very high concentration of silica, which dulls knife blades very fast (and saw blades and other woodworking tools, which is why woodworkers don’t like to use it). There are also some very hard woods like cherry and cocobolo that while attractive to look at, are hard enough to beat a knife blade dull during even light chopping. There are also a few woods like black walnut that are durable and beautiful to look at, but are toxic to humans; a black walnut splinter will raise a pustule in under an hour as the walnut tree’s immune system clashes with the human immune system; walnut sawdust in the lungs can kill a person. So it would behoove anyone buying wooden kitchen implements to learn something about the wood species they are thinking of buying. For example, bamboo kitchen utensils are great because they’re durable, but the silica in them can erode non-stick material in pans, and bamboo cutting boards dull knives. Maple, on the other hand, is one of many hard, attractive woods that are good for cutting boards, and since the sap is proven safe to human by virtue of centuries of condensing its sap into pancake syrup, it is also a safe choice for a cutting board.

One other caveat: I recently used for the first time one of the silicon “cutting mats” that have become popular recently. I noticed quickly that if the bottom isn’t thoroughly dried when washed or rinsed between processing different foods, it’s very slippery and conducive to facilitating an accident, as the scar on my index fingertip, which hadn’t been cut in decades of chopping, slicing, and chiffonade, will attest. ;-)

If I can be of further assistance, I’d be delighted. Have a wonderful day.

David Jackson

Chef and woodworker


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