Updated: 24 Jun 2009

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Introduction

A sharp knife is a safer knife. We tested 10 knife sharpeners costing between $19 and $215.

Blunt knives can cause accidents because you have to apply more pressure when cutting, increasing the risk of slips and mis-cuts.To keep your knife sharp you should ideally hone it on a steel each time you use it. This will realign the blade, but eventually it will need sharpening to create a new edge.

We found four knife sharpeners to recommend, and also explain what to look for and how to care for your knives.

Models we tested

This report contains test results and recommendations for the following models of knife sharpener:

What we found

Our test

The tester sharpened each knife following the manufacturer’s instructions. If the result was not satisfactory sharpening continued until an acceptable result was achieved. A sharp knife would slice an A4 sheet of paper from the edge without tearing it and cut the skin of a tomato easily and cleanly under its own weight.

We also wanted to see how easy the sharpeners were to use, rating them for ease of sharpening, safety and instructions.

Our tests used 20cm Victorinox chefs’ knives, one knife for each sharpener. Each knife was tested for sharpness when new, then put through a blunting process.

Performance

Six sharpeners achieved a top performance score of 90. They required little effort to produce a blade with a very fine smooth edge. The Wusthof Sharpener 4344 was the only sharpener not to achieve a good or better result. It took many strokes to sharpen the knife.

Ease of use

Ease of sharpening
The Cuisinart KS-80A (pictured right) was the easiest to use. It’s an electric sharpener – all you have to do is draw the blade through the slots. The Russell Hobbs RHKS1000 was also electric but it took a lot of passes to sharpen the knife.

Safety
The Accusharp Knife and Tool operated differently from the others – the knife was held still while the sharpener was moved across the up-turned blade. A finger guard is provided for protection but it’s still important not to apply heavy pressure as you might lose control of the knife.

The other manual sharpeners had to be held steady with one hand while sharpening. These sharpeners should have a non-slip base. The Wiltshire WILT595064 Knife Sharpener had a base which could slide across a bench under pressure.

Instructions
The Accusharp, Chef’s Choice, Cuisinart and Russell Hobbs were the only sharpeners with instructions which provided safety advice.
 

We recommend

• 

  Cuisinart KS-80A

  $215

  Good points

  Excellent performance - achieves a smooth edge. Excellent ease of use score. Very little effort required. Claims to sharpen serrated knives (but not tested). Safe to use.

  But

  Not very portable - requires electrical connection. Expensive.

  User Reviews 0
• 

  Chef's Choice 2-Stage Sharpener 450

  $60

  Good points

  Excellent performance - achieves a smooth edge. Very easy to use.

  But

  Care required - the knife may damage the bench if it slides out of the sharpening slot. May be hard to find - contact sales@houseofknives.co.nz.

  User Reviews 1
• 

  Furi Ozitech Diamond Fingers FUR 626

  $45

  Good points

  Excellent performance - achieves a smooth edge. Very easy to use. Easily portable in a convenient pocket-size pack. Safe to use.

  But

  May be hard to find - contact sales@sheldonandhammond.co.nz

  User Reviews 1
• 

  Minosharp Water Sharpener 220/GB

  $44

  Good points

  Excellent performance - achieves a smooth edge. Very easy to use.

  But

  Care required - the knife may damage the bench if it slides out of the sharpening slot.

  User Reviews 0

Checklist

What to look for in a knife sharpener

• Multistage: The best edge is achieved with a sharpener with at least two stages – one for coarse cutting and one for fine honing.
• Sharpening materials: Sharpeners using stone, ceramic or diamond materials will achieve a fine honed edge. Sharpeners using tungsten remove material along the edge of the knife leaving microscopic serrations. This serration cuts well at first but the blade may wear out more quickly.

Keeping the edge

Your knife will cut better and need sharpening less often if you look after it.

• Cut only on a wooden or polycarbonate chopping board.
• Hand wash and dry the knife immediately after use, especially if it has been in contact with acidic foods such as tomatoes or citrus fruit.
• Store the knife in a knife block (or a knife guard if you keep it in a drawer) to protect the blade – and your fingers.

If you don’t want to risk damaging an expensive knife get a professional to sharpen it. Hardware stores and specialist kitchen shops can suggest a knife sharpening service.

Report by Bev Frederikson.