How to Sharpen a Japanese Knife

You need a 1,000-grit stone, a damp towel, ten minutes and a permanent marker. That is the whole equipment list.

1. Prepare the stone. If it is clay-bonded — a King, a Suehiro — submerge it until the bubbles stop, about 10 to 15 minutes. If it is splash and go — Shapton Glass, Naniwa Professional — wet the surface and start. Put a damp folded towel under it so it cannot slide.
2. Set the angle: 15 degrees per side. Two stacked US quarters under the spine of a typical kitchen knife is close. Color the bevel with a permanent marker first — it is the only way to verify you are on the bevel and not the shoulder. More ways to find the angle.
3. Make three passes and check the marker. Ink gone evenly across the bevel means the angle is right. Gone only at the apex means you are too steep; only at the shoulder means too shallow. Adjust and repeat before doing anything else.
4. Work one side until a burr forms along the full edge. Light pressure, whole-body movement, wrist locked. Work in sections — heel third, middle third, tip third — and lift the handle slightly as you reach the curve so the contact point stays on the stone. Keep the stone wet.
5. Check for the burr. Run a fingertip across the edge from spine to edge — never along it — on the side you have not been working. A burr catches slightly. If there is no burr anywhere, keep going; if there is a burr for most of the length and not at the tip, work the tip.
6. Flip and repeat. Same angle, same pressure, same number of passes roughly. Work until the burr flips to the other side along the full length.
7. Refine, if you have a finishing stone. Move to 3,000 or 6,000, same angle, lighter pressure, fewer passes. Alternate sides, finishing with single alternating strokes to minimize the burr.
8. Strop. Ten to fifteen edge-trailing passes per side on leather with compound. Spine first, edge dragging. Never lift the spine — that rounds the apex and undoes everything. Stropping in detail.

• Look at it. Hold the edge up under a light and look straight down at it. A dull edge shows a thin bright line where the flat apex catches the light. A sharp edge shows nothing.
• Feel for the burr. After stropping, there should be no burr on either side. If there still is, strop more lightly.
• Cut a tomato. The real test. Rest the edge on the skin with no downward pressure and draw it back. A sharp knife parts the skin on the draw. A knife that needs pressure is not finished.

1. Too much pressure. It flexes the blade, rounds the apex and dishes the stone. Let the abrasive cut.
2. Stopping before the burr. No burr means you never reached the apex — you polished the bevel of a dull knife.
3. Neglecting the tip. The curved section gets far fewer passes than the flat because people do not lift the handle. Work it deliberately.
4. Letting the stone dry. A dry stone loads up with steel swarf and stops cutting. Keep water on it.

The full list is on common sharpening mistakes, and if the knife is still not sharp after all this, the diagnostic is here.

None of the above applies unmodified. A deba, yanagiba or traditional kiritsuke is ground on one face with a hollow on the other, and the technique is different in ways that matter. Start here instead.