Wooden cutting boards are made in two main ways. In an edge-grain board, long strips of wood are glued side by side, so the fibers lie flat along the surface. In an end-grain board, short blocks are glued together standing up, so the cut ends of the fibers face up, like the bristles of a brush. End-grain boards are widely said to be kinder to knives, and the explanation sounds convincing: the blade slips between the upright fibers, which then close again, while on edge grain it must cut across them.
A belief like this is easy to repeat but hard to check at home. A cooking magazine's test kitchen, working with a robotics lab, checked it. A robot made 5,000 cuts on each board with a brand-new knife, stopping every 200 cuts to measure the blade's sharpness. There was no clear difference in sharpness between the knives used on the two kinds of board.
The test did find other differences. Each time they were oiled, the end-grain boards soaked up about four times as much oil as edge grain. When water soaks into these boards, the wood swells and shrinks, which puts stress on the many glue joints holding the blocks together. The type of wood mattered too: a soft wood was scarred far more deeply than harder woods such as maple.
A convincing explanation, in other words, is not the same as a measured result. The fibers may well part and close as described. What the robot showed is that, for the knife, this made no clear difference.
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