How to choose the best Professional and Home Sharpeners
Jan 5, 2010Yuen Kit Mun
While there are differences between the various models of sharpeners, most home users will not be able to see significant differences in the sharpness of the knives. There still are however, some other considerations.
Examples of brands include Chef’s choice (Diamond Hone), Smith’s Edge (Diamond Edge Pro), Shun, McGowan (Firestone, Diamondstone) and Wusthof. Prices range from $30 to over $100 for consumer models.
Professional models for commercial use cost hundreds of dollars. They are designed for heavy duty daily use. However they don’t necessarily result in sharper knives.
Knife Edge and Bevel Basics
Understanding knife sharpeners means understanding bevels – the shape and slope of the sharpened blade edge.
Most knives have double sided bevels: both sides of the knife are sharpened the same way. Chisel grind single sided bevels (one side of the knife is flat, has no bevel) are rare.
The bevel can be:
- Flat. a cross-section of the edge looks like a “V”.
- Concave (looks like the bottom of a ship) or “hollow grind”. the edge is thinner and weaker.
- Convex (looks like a melon seed). This is stronger.
The angle of the bevel will determine the sharpness and strength of the knife edge. Most Western (American and European) kitchen knives are sharpened at 20 to 25 degrees. Japanese or Asian knives typically use a sharper 15 degree angle. They cut better but the edge blunts more quickly and needs to be sharpened more often. Many manufacturers will sell both types of sharpeners.
For most home cooks, the type of bevel isn’t significant. the knife edge is reset to whatever bevel shape and angle used by the knife sharpener. the important thing is to use the same sharpener so that the blade edge isn’t constantly reshaped.
Grinding Stone Materials
The material used to make the grind stones doesn’t matter much. the stones will be hard enough to grind steel knives, and last for hundreds or thousands of sharpenings. Diamond-coated stones are the hardest but ceramic and other stones work well too.
Single side and Double side Sharpeners
The simplest designs sharpen both sides at the same time, using interlocking grinding wheels. the knife is placed between the vertical wheels, cutting edge down, and slowly pulled through as an electric motor turns the wheels.
Advantages
- Easy to use. the blade is pulled through the sharpener a few times, until it is sharp enough.
- No blade guides (that might scratch the knife) are needed.
- Simple and reliable rotary mechanism.
- Open slot design means that more of the blade can be sharpened (the bolster of forged blades isn’t blocked by blade guides).
Disadvantages
- Not suitable for chisel grind knives.
- Creates concave bevels that are thinner and weaker.
Other sharpeners will sharpen only one side of the knife at a time. There are two sharpening slots, one for each side of the knife.
Advantages
- Often creates a flat bevel, stronger than a concave bevel.
- Can be used to sharpen chisel grind knives.
- Can sometimes sharpen serrated knives by sharpening the flat side of the serrations.
Disadvantages
- Can be difficult to hold the knife at the correct angle, even with spring or magnetic blade guides.
- Blade guides can scratch the knife.
- Grinding action can be slow, less efficient.
Multi-stage Knife Sharpeners
More advanced knife sharpeners have multiple stages or slots (not counting the left and right slots used by single sided sharpeners):
- The first stage has a coarse stone that quickly shapes the basic knife bevel. It is used for very blunt knives and will leave visible scratch marks on the bevel.
- The second stage has a medium stone that removes the scratches created by the first stage, for a smoother and sharper edge. the bevel now looks smooth but dull gray. some sharpeners stop here.
- A few sharpeners have a third finishing, polishing, buffing or stropping stage. very fine stones, or plastic disks, polish the bevel to a mirror finish and create a razor-sharp cutting edge.
Some sharpeners increase the grind angle at each stage, creating a roughly convex bevel. the edge is stronger but the subsequent stages don’t cover up all the scratches from the first stage, so the cosmetic finish isn’t as good.
Single-stage sharpeners are equivalent to the second stage, using medium grit stones for shaping the bevel and creating the final cutting edge. For practical purposes, they can work just as well as multi-stage sharpeners.
The best Electric Knife Sharpener
Most models from the major manufacturers should give good results. Differences in sharpness will not be noticed by the average cook. Sharpeners with interlocking grind wheels that sharpen both sides at once, are an especially safe choice. Single-stage sharpeners will be more than good enough for most home use.
Because electric sharpeners quickly remove a lot of metal, it is best to try out a new sharpener with a cheap knife first. It is also important to read the instruction manual.