How do I sharpen kitchen knives?

The difference between honing and sharpening, how to use a whetstone or pull-through, and how to keep an edge once you have one.

Difficulty: intermediate
Time: 30 min
Read: 3 min
Safety: caution

Short answer

Honing with a steel realigns an edge and should be done often; sharpening removes metal to create a new edge and is needed occasionally. For sharpening, a whetstone at roughly 15–20° per side gives the best result. Pull-through sharpeners are faster but remove more metal and give a coarser edge.

A blunt knife is more dangerous than a sharp one, because it slips instead of cutting and needs more force. The confusion most people have is between honing and sharpening: a steel doesn't sharpen anything, it straightens a rolled edge. When honing stops helping, the knife genuinely needs sharpening.

Safety

Always sharpen away from your body, on a stable non-slip surface. A freshly sharpened knife is far sharper than you're used to — test it on paper, not your thumb, and be deliberate with the first few cuts you make with it.

What you'll need

Whetstone (combination 1000/6000 grit is a good start)
Honing steel
Damp cloth to stop the stone sliding
Angle guide (optional)
Paper to test the edge

Holding a knife at a consistent angle on a stone

Step by step

Work out whether the knife needs honing or sharpening: try slicing a sheet of paper.If it catches and tears, hone it first. If honing doesn't fix it, it needs sharpening.
To hone: hold the steel vertically, tip on a board, and draw the blade down at about 15–20°.Light pressure, alternating sides, 5–10 strokes each. You're straightening, not grinding.
To sharpen, soak a water stone for 10 minutes and set it on a damp cloth.The cloth stops the stone sliding, which is the main safety issue with stone sharpening.
Hold the blade at about 15–20° to the stone — half of a 45°, then half again is a reasonable guess.European knives are usually around 20° per side; Japanese knives often 15° or less. Consistency matters more than the exact number.
Push the blade across the stone as if slicing a thin layer off it, from heel to tip.Keep the angle constant through the stroke. The most common error is lifting the spine as you reach the tip.
Work one side until you feel a burr along the whole length of the other side.Run a fingertip carefully across (not along) the edge — the tiny lip of metal is the burr, and it means you've reached the edge.
Repeat on the other side, then reduce pressure for a few final alternating strokes.The light finishing strokes remove the burr and leave a clean edge.
Move to the fine grit side and repeat with light pressure, then test on paper.It should slice cleanly through a held sheet without catching.

Tips

Hone every few uses and sharpen a few times a year. That routine keeps a knife permanently usable with minimal effort.
A wooden or plastic board preserves an edge. Glass, stone and ceramic boards destroy one within a few cuts.
Never put good knives in the dishwasher — the detergent is abrasive and knives knock against everything else.
If you're not confident, a professional sharpening service is inexpensive and will restore a badly damaged edge better than a first attempt on a stone.

Common mistakes

Confusing honing with sharpening — A steel removes almost no metal. If the edge is genuinely worn, honing achieves nothing.
Varying the angle mid-stroke — Produces a rounded edge rather than a sharp one, and it's the most common beginner error.
Using a pull-through on good knives — They remove a lot of metal at a fixed angle and shorten the knife's life considerably.
Storing knives loose in a drawer — The edges knock against everything and blunt within days.

Questions people ask

How often should I sharpen?

Hone every few uses; sharpen when honing stops restoring the edge — typically two to four times a year for home cooking. Heavy use or a hard board means more often.

Are pull-through sharpeners bad?

They're fast and better than a blunt knife. But they grind at a fixed angle, remove a lot of metal, and leave a coarser edge. For inexpensive knives they're a reasonable trade; for good knives, use a stone.

What angle should I use?

Roughly 15–20° per side for most Western kitchen knives, and 15° or less for many Japanese ones. Check what your knife came with — but consistency matters more than precision.