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2 Aug 2021

What's the best way to sharpen my chef's knife?

Find out how to test the sharpness of your chef's knife and the different ways to spot and fix a dull blade

A dull chef's knife makes cooking an unnecessary chore and can lead to a painful hand and wrist.

Find out how you can check if your blade is blunt and how to sharpen it.

Plus we explain the key differences between using a handheld knife sharpener and a whetstone to sharpen your chef's knife at home.

Time for a new knife? Check out our guide to the best chef's knives

How to tell if your chef's knife is dull

Man checking a knife

Kitchen knives dull over time and sometimes it can be hard to tell how badly they need to be sharpened, as you use your strength to compensate for their dullness.

An easy way to spot the areas of your knife that need a bit of TLC is to look at the blade directly from above while shining a light across the cutting edge of the knife.

Any areas of the cutting edge that reflect the light and appear shiny have been dulled.

Another way to test the sharpness of the blade is to slice through a piece of paper. For a sharp knife this should be effortless, so if it's not it's time to use a knife sharpener.

What you need to know about knife sharpeners

A lady sharpening a knife

Here are five things we learnt from our knife sharpener tests:

  • You should sharpen your knife little and often, ideally after a couple of hours of use.
  • For the best results combine a whetstone with a honing steel, but only if you have practised this: if you do it wrong, you risk damaging the cutting edge of your knife.
  • In most cases, a knife sharpener with two grinding stones will have a coarse one for sharpening and a fine one for honing. When you hone a blade you are realigning the cutting edge to smooth out microscopic bumps and jagged edges.
  • Handheld sharpeners are designed to keep your blade's edge sharp. You should use them to top up the blade after every few hours of use. They aren't great with fully dulled knives - for that it's best to use a whetstone.
  • Some knife sharpeners allow you to replace the sharpener wheel when needed, but others don't, so bear this in mind if sustainability is important to you.

Find out the best knife sharpeners and how to use them.

Is a whetstone better than a sharpener?

knife sharpener and whetstone

Whetstones are sometimes known as sharpening stones and are essentially a two-sided block of coarse stone (one side more coarse than the other) and a base/holder.

Once you've mastered a whetstone it does sharpen knives brilliantly, but you'll end up with a mess wherever you choose to use it, which won't happen with a knife sharpener.

For most people, a handheld knife sharpener will meet your sharpening needs as long as it is used on a regular basis.

How we tested chef's knives and knife sharpeners

knife sharpener

Chef's knives tests:

To test chef's knives we first examined the blade's cutting edge to see how dull they were.

We then used each knife in our test to cut through paper and cucumber as well as raw chicken breast, butternut squash and tomato.

After this, we tested how easy they were to use to dice an onion, mince garlic and julienne a carrot.

Finally, we checked how well they had retained their sharpness with a repeat examination and paper test.

Handheld sharpener tests:

To test knife sharpeners, we first blunted one knife for each sharpener.

We then used each sharpener to file the blunted knives and examined the blades for dullness.

We then repeated the cutting tests with paper, butternut squash and tomatoes.

We purchased all the products we tested and no food was wasted to bring you the results.

See all the best knife sharpeners.