How to Sharpen a Knife

Most kitchens have dull knives. Not because the knives are bad — nobody told us how to maintain them. A whetstone costs less than a decent meal out and lasts decades. Everything else you likely already own.

The tools

Which knife to practice on

What a knife edge actually is

A knife blade tapers to a V-shape at the edge. Sharpness depends on how fine that V is — how thin the metal at the very tip (the apex) becomes. Sharpening removes metal from both sides of the V, re-establishing a fine apex. Over time, use bends and rolls the apex microscopically. Honing (the steel) pushes it back into alignment. Eventually, honing isn't enough. The apex has been rolled too many times and needs to be re-cut with a stone.

The angle

The angle at which you hold the knife against the stone determines the edge you create. Shallower angles create sharper but more fragile edges. Steeper angles create more durable but less razor-sharp edges.

The strokes

Wet the stone with water (most whetstones are water stones, so check yours). Hold the knife at your chosen angle and push the edge forward along the stone in a sweeping arc, as if you're trying to slice a thin layer off the surface. Work from the heel of the blade to the tip in one smooth stroke. This is the push stroke. Some people use a pull stroke (drawing the edge toward them). Both work. Pick one and be consistent.

Count your strokes. Do 5–10 strokes on one side, then 5–10 on the other. Alternate. You're removing metal from both sides equally to maintain the V.

The burr

As you sharpen on the 1000 grit side, you'll raise a burr — a tiny wire of metal that folds over to the opposite side of the edge. Run your thumb gently across (not along) the edge on the side you haven't been sharpening. If you feel a slight catch or roughness, that's the burr. Raising a burr across the full length of the blade means you've sharpened that side enough. Switch sides, repeat, then move to the finer grit.

Testing as you go

Honing: the daily habit

Hold the honing steel vertically, tip on a folded cloth. Draw the knife edge down the steel at 20°, alternating sides, 4–5 strokes each. This takes 30 seconds. Do it before every cooking session and you'll need the stone far less often.

Work through this sequence with your chef's knife and a combination whetstone. Set aside 20 minutes for your first session. It'll take 5 once you have the feel.

1. Soak the whetstone in water for 5–10 minutes until bubbles stop rising. Place on a damp cloth on a stable surface.
2. Hold the knife at your angle (15° for Japanese, 20° for Western). Index finger on the spine, other fingers on the handle, thumb on the flat of the blade near the heel for control.
3. Push the edge forward along the 1000 grit stone in a sweeping arc, applying light, consistent pressure. Heel to tip in one stroke.
4. Count 8 strokes. Check for a burr on the opposite side by running your thumb gently across (not along) the edge.
5. Flip the knife. Repeat 8 strokes on the second side. Check for a burr on the first side.
6. Alternate: 5 strokes each side, then 3, then 1, then 1. This gradually refines the edge to the centre.
7. Move to the finer grit side (3000+). Repeat 5–6 alternating strokes each side with lighter pressure.
8. Rinse the blade. Test on paper: it should cut cleanly with a single smooth stroke.
9. Hone on the steel: 4–5 strokes per side to align the new edge.
10. Rinse again, dry, and test on a tomato. No pressure required. The knife does the work.

The sharpeners to learn from

• Murray Carter — Canadian-born bladesmith trained in Japan; 17th generation Yoshimoto blade tradition; his YouTube tutorials on Japanese knife sharpening are the gold standard
• Korin Knife (New York) — Long-running Japanese knife specialist; their online sharpening guides and in-person classes are excellent; particularly good on single-bevel knives
• Josh Donald (Bernal Cutlery) — San Francisco knife sharpener and retailer; deeply practical video tutorials on freehand sharpening for the home cook

Best resources