The Knife
Sharpening Guide

This guide covers double bevel knives sharpened on whetstones. Before you touch a stone, confirm that is what you have.

Confirm You Have a Double Bevel

Hold your knife up and compare both sides. On a double bevel knife, both sides look similar, though the bevel size may vary. This covers most Western knives and many Japanese knives: gyuto, santoku, petty, bunka, nakiri, and sujihiki. They are sharpened on both sides using the same process, typically at 10 to 15 degrees per side.

If the two sides look dramatically different, with a wide bevel on one side and a hollow back on the other, you have a traditional single bevel knife such as a yanagiba, deba, or usuba.

There is no fixed schedule. The rule is simple: sharpen when the knife is not working the way you want. Be mindful while you work and pay attention to how the knife feels.

Signs Your Knife Needs Attention

• It is slipping over the surface of foods like tomato or fish skin instead of biting in
• It steers to one side while cutting
• It wedges in dense foods instead of moving through cleanly
• Cuts feel inconsistent or require more force than usual

Building a Rhythm

As a professional, consistency matters. A knife that performs the same way every time makes your work more predictable and precise.

• Sharpen at the end of each shift
• Touch up the edge on a finishing stone before and during service
• Never let the knife get so dull that it requires heavy work to recover

A complete setup has five components. The first three are the critical ones. Skill matters more than equipment.

Stone Types

Keeping Your Stone Flat

A hollow or dished stone makes it impossible to maintain a consistent angle. Flatten regularly:

1. Draw a pencil grid across the entire surface of the stone
2. Rub the stone on your flattening plate using long strokes
3. Rotate the stone 90 degrees periodically to avoid uneven wear
4. Continue until all pencil marks are gone
5. Round over or chamfer the edges slightly to prevent cracking and to protect your hands

Always inspect the knife before touching a stone. Sharpening a bent or twisted blade will make the problem worse.

• Look at both sides: are there visible chips, scratches, or profile problems?
• Sight down the spine: hold the knife at eye level and look along the spine from heel to tip. Do this on both sides and look for bends.
• Sight down the edge: do the same looking from the tip toward the heel. Use a straight background line, like a door frame, as a reference.
• Check for twist: hold the knife horizontally at eye level and check whether the edge sits level with the spine. If the edge rises or drops on one side, the knife is twisted.
• Check steering: when you use the knife, does it cut straight or drift to one side?

Good body position makes the whole process easier and more consistent. Stand slightly to the side of your stone, think of a relaxed boxing stance, with your knuckles overhanging the bench edge.

Grip

• Hold the knife in a pinch grip: thumb and the side of the index finger knuckle pinching the blade near the bolster, middle finger tucked into the choil
• Left side of the knife: thumb moves to the spine, index finger toward the heel
• Right side of the knife: index finger moves to the spine, thumb toward the heel

Find Your Angle

The safe range for Japanese double bevel knives is 10 to 15 degrees per side. Lower means sharper but more fragile. Higher means more durable but less acute. Drag the slider to see where every angle in this guide lives.

Step by Step

1. Soak your stones as required.
2. Position fingers on the blade as close to the edge as possible without touching the stone.
3. Apply pressure on the edge trailing stroke (pushing the spine forward) and relax on the return. Medium pressure is around 1500 g. Finishing is around 100 g.
4. Move straight forward and straight back. The angle of approach is 45 to 60 degrees relative to the stone surface (not the sharpening angle).
5. As you approach the tip, lift the spine and rotate slightly back toward it. This is the tip adjustment.
6. Sharpen the first side until you feel a consistent burr from heel to tip.
7. Repeat on the second side until you feel a consistent burr on the other side.
8. Move to your finishing stone and repeat on both sides.
9. Strop the edge to weaken the burr.

Understanding the Burr

The burr, also called a wire edge, is a thin flap of metal that forms on the opposite side from where you are sharpening. It is essential feedback.

• If you have a burr, you are hitting the edge and removing fatigued steel
• If you have no burr, you are probably not reaching the edge
• The burr must be even from heel to tip. Uneven burr means uneven metal removal, and the profile will change over time

To feel for it: place your thumb on the side you just sharpened, then drag your index finger along the opposite side, moving from spine toward edge. A burr feels like a faint catch or roughness. Your index finger has the most nerve endings of any digit. Use it.

Progression and Burr Removal

Work through your stones in order: coarse (if needed), medium, finishing. On each new stone you are replacing coarser scratches with finer ones. Stropping then removes the burr, the same motion barbers use on a leather strop:

• Cover the entire length of the knife in a single stroke, alternating sides
• Use edge trailing strokes only
• Very light pressure: around 100 to 200 g
• The goal is to weaken the burr's connection so it can be removed cleanly

For final removal, use the blue non scratch side of a kitchen sponge (not green, which has abrasive). Brush along the edge lightly. This is highly effective and reliable.

Asymmetry

If your knife steers to one side while cutting, one side of the bevel is exerting more pressure than the other. Fix it by spending more time on the side it steers toward without changing the angle, slightly reducing the angle on that side to create more surface area, or a combination of both. On laminated (clad) knives, keep the apex roughly centred so you do not sharpen through the soft cladding into the hard core steel.

The Sharpie Trick

The most useful diagnostic tool available. Colour the entire bevel with a Sharpie permanent marker, let it dry completely, sharpen a few strokes, then read where the ink was removed. The pattern tells you exactly what your hands are doing. Tap through the seven patterns below.

Interactive · Reading the Sharpie

← Previous 1 / 7 Next →

Use Sharpie constantly while learning. Colour, dry, sharpen a few strokes, look, adjust, repeat. Remove it at the end with acetone and a cotton pad.

This is the most underappreciated aspect of knife performance. Nothing matters more.

Every time you sharpen at your normal angle, you move slightly higher up the blade and the knife gets thicker behind the edge. Over time, a knife that felt effortless starts to wedge in foods, require more force, and feel dead.

Thinning corrects this. It is done at a much lower angle than sharpening, typically 2 to 4 degrees per side, and must contact at least one fifth of the blade height to have a meaningful impact. One third or halfway up the blade is better.

When Thinning Is Needed

• The knife wedges in dense vegetables or fish
• Starting cuts feels harder than it used to
• The bevel has grown noticeably wider over time
• Pinch the blade and feel how thick it is behind the edge

In an ideal world you thin a little every time you sharpen. In practice, most people sharpen regularly and thin when performance drops. Both approaches work.

Micro Bevels

A micro bevel is a very small secondary bevel added at a slightly higher angle at the very edge. It sacrifices a tiny amount of sharpness for durability and chip resistance.

The whole guide, condensed to a bench side reference. Tick off the checklist as you work.

Sharpening Checklist

Common Mistakes and Fixes

Stone Grit Guide