We look at simple, cheap yet effective knife sharpeners that anyone can use – just pull the knife through the slot. They can quickly revive an old, blunt knife or touch-up a heavily-used favorite knife.
Many people put up with blunt kitchen knives because they think that sharpening them is just too difficult. With these gadgets, now there’s no excuse. Experts might look down on these no-skill devices but they actually come quite close to delivering professional results.
They will create razor-sharp or close to razor-sharp edges. Tomato-slicing sharpness is enough for kitchen use and this is easily achieved with these tools. Most are small and store easily into a kitchen drawer. Many are even light even to take with you when hunting or backpacking.
Their main disadvantage is that the edge produced is not always as smooth as the edge that you can get from sharpening on a fine stone (but some sharpeners come very close). The edge might not last as long, requiring more frequent touch-ups, causing the knife to wear down more quickly. You might not want to use these on expensive knives.
But that’s okay because the dirty little secret about kitchen knives is that a properly sharpened cheap knife will outperform a blunt expensive knife. We all know people who have expensive but blunt knives in their kitchen – a total waste of money. The cheap knife might have softer steel but as long as you sharpen it frequently, that won’t affect its performance.
Some badly-damaged knives don’t work well on these sharpeners – you’ll only get a jagged edge. You’ll need to grind down the edge with a flat stone first before using the knife on the sharpener.
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Tungsten Carbide and Ceramic V Sharpeners
These use tungsten carbide blades and/or ceramic rods that are placed in a V shape. The knife is pulled through the V.
The tungsten carbide blades are used to quickly shape the knife blade. They are quite aggressive and will shave off visible steel strips from the knife. Up to 10 strokes will sharpen even the dullest knife.
The ceramic rods are used to polish the edge of the knife, after it has been shaped by the tungsten carbide blades. This creates a smooth, sharp edge that is similar to what you would get from using a fine high-grit sharpening stone. For weekly or monthly touch-ups of the knife, you’ll only need to use the ceramic rods.
Some sharpeners, such as the popular AccuSharp, only have the tungsten carbide blades and don’t have ceramic rods for polishing the edge. This isn’t ideal but will be good enough for most people.
The main problem with V sharpeners is that they don’t last long, a few years of average use at best. This is because the tip of the V wears out and doesn’t sharpen well after a while.
Steel and Ceramic Disk or Wheel Sharpeners
These are like the V sharpeners, but use round disks instead of flat blades or rods. They can be a bit confusing because they combine the functions of tungsten carbide V blades and ceramic V rods in one. The original designs are decades old and are made out of about 2 to 8 interlocking steel wheels. Brands include Ekco, BOJ, Rada and Pedrini.
The sharpening V is made from the valley where the wheels meet. The outer corner of the wheels is used like a tungsten carbide V blade to scrap off any excess metal from a blunt edge. This sometimes doesn’t work well and the edge becomes jagged. In these cases, you’ll need to roughly shape the edge on a sharpening stone.
After the edge has been roughly shaped, you lightly draw the knife over the top of the wheels (the smooth edge, not the corner) to hone the knife.
Because the wheels turn, wear on the wheels is randomly spread out (you can help by turning the wheels before each use). This makes the wheels last a lot longer compared to the V sharpeners, even with the steel wheels being softer than tungsten carbide or ceramic.
Newer designs, notably those from Henckels, use a combination of steel and ceramic wheels. The steel wheels are used to quickly scrap off any excess metal from a blunt edge, while the ceramic wheels are used to hone the edge. As ceramic is harder than steel, the honing process is faster compared to using steel wheels.
On some models, the steel and ceramic wheels are placed in the same slot – one pull and the knife edge passes through both sets of wheels.
Other models put the steel and ceramic wheels in different slots, allowing you to have more control over whether you want to shape the edge (steel wheels) or only hone an edge that has already been shaped (ceramic wheels).
Stone Wheel Sharpeners
Sharpening stones are usually not used in simple kitchen slot sharpeners because the stones wear out quickly, compared to tungsten carbide, ceramic and steel. A V or disk stone sharpener would be quickly notched by the knives it sharpened.
Sharpening stones need to have the knife scrapped across their whole surface, not just at one point. The MinoSharp sharpeners manage to achieve these through an ingenious mechanism that uses stone wheels that are placed diagonally across a plastic slot. As you pull the knife through the slot, the knife contacts the stones and spins them, automatically grinding the edge of the knife.
This gives you a nicely ground edge, combining the speed of tungsten carbide V blades in quickly fixing a blunt blade, with the finesse of a sharpening stone. There are no jagged edges like you would get with tungsten carbide. There are additional wheels with finer grit stones, to further refine the edge.
As with other sharpening stones, the MinoSharp needs water to stop the ground-off steel from gunking up the stone’s surface, making it less able to grind the knife. You need to fill up the MinoSharp with some water for it to work properly.
The main drawback is that even with the wear on the stones distributed across the surface of the wheel, the stones do wear out quickly, as quickly as any other sharpening stones. Another drawback is that due to the angled stone wheels, the rear quarter inch or so of one side of the knife might not get sharpened properly.
The Best Kitchen Knife Sharpener
All of the sharpeners described here work reasonably well. All have their own advantages and disadvantages. Considering how cheap most of them are, you might want to buy a few and see which suits you best.
The V sharpeners are especially cheap and easy to use, which makes them good sharpeners to start with.