How to sharpen kitchen knives

A dull knife is more dangerous than a sharp one — it requires more force, slips more easily, and crushes food instead of cutting it. A whetstone is the tool that actually sharpens: it grinds a tiny amount of metal away to form a fresh edge. Soak the stone in water for 10–15 minutes first (skip this for oil stones). Hold the knife at a consistent 20° angle for Western-style chef’s knives, or 15° for Japanese blades — about the height of a matchbook or two stacked quarters under the spine. Push the edge across the stone like you’re trying to shave a thin slice off the surface, working one side until you feel a slight burr — a tiny lip of metal — on the opposite side. Flip and repeat. Then switch to the finer-grit side and do both sides again to polish the edge.

A honing steel — that rod that comes with knife blocks — doesn’t sharpen. It straightens the microscopic edge that bends over with regular use. Run the blade along the steel at the same angle, alternating sides, 5–10 passes per side, once a week. Most home cooks only need to actually sharpen their knives two to four times a year if they hone regularly. A sharp knife should slice through a ripe tomato with no pressure — if yours won’t, it’s time.

A reliable whetstone is a small investment that makes this easier: whetstone.