Among makers of electric knife sharpeners, Chef's Choice is by far the most popular and a number of their models place high in both comparative professional tests and user reviews. One standout is the Chef's Choice 1520 AngleSelect (Est. $160), which allows you to sharpen knives with a 15-degree edge angle and those with a 20-degree edge. This sort of versatility is becoming more important than ever because, although 20-degree edges are predominant in Western kitchen cutlery, it's not unusual for a kitchen to have a couple of 15-degree Asian-style knives as well, and some Western manufacturers have begun introducing 15-degree edges too.
Testers at a prominent cooking magazine say the 1520 AngleSelect's sharpening process accurately ground both Western and Asian-style knives "to like-new sharpness in a matter of minutes," and its guides hold your blade at just the right angle, eliminating any guesswork. Although the 1520 AngleSelect has three sharpening slots, you only use two of them on a given blade; either slot one for a 15-degree Asian blade or slot two for a 20-degree Western blade, followed by a few passes through slot three for stropping and polishing. Spring-loaded blade guides help keep your knife at just the right angle.
Users say that the instructions for the 1520 AngleSelect are well-written, the sharpening process is easy to master, although you will want to read the directions and practice on a cheap knife to master the even pull that's required for consistent results. They also say that the diamond polishing disks in slots one and two work well even on the very dense steel found in high-quality cutlery. In fact, one user warns that knives get so sharp, so quickly, that if you're not careful and gentle while using this device, they can cut right into the plastic casing beneath the sharpening slots.
This sharpener can handle both single/double-beveled straight blades and serrated blades. The manufacturer recommends about 20 strokes to sharpen a blade, but users say that just four or five is enough for most. In fact, a few worry that the sharpening disks in stages one and two are too aggressive and remove too much metal. This is useful if your knife's blade is very dull, but if the blade is still in good shape you might be able to sharpen it with a few passes through the stropping slot three.
Fully encased sharpeners like the Chef's Choice 1520 AngleSelect are an excellent choice if you're at all concerned about the safety of using a manual sharpener; you'd be hard-pressed to get a finger anywhere near the 1520 AngleSelect's grinding disks, even if you tried. The sound is usually just a quiet buzz, although several users say that louder noises presaged trouble with the sharpening disks. If you notice a marked decrease in sharpening or polishing quality, this usually means it's time to wipe off the magnet in the underside of the device that collects metal shavings made during the sharpening process.
If you have only 15-degree knives in your household, you might prefer a Chef's Choice sharpener that's made exclusively for 15-degree knives, which frees up all three of the sharpening stages for use on the one knife. The Chef's Choice 15 Trizor XV (Est. $160) took top honors from a noted test kitchen; the testers said that it not only sharpens knives beautifully but can even restore a nicked blade, and the sharpened blade actually won a blind performance test against a factory-new version of the same knife. The Chef's Choice Trizor sharpener can also put a sharper, thinner 15-degree edge on your 20-degree knives.
Like the Chef's Choice 1520 AngleSelect, the Chef's Choice 15 Trizor uses all-diamond abrasives in slots one and two, plus a flexible stropping disk in slot three for a smooth, polished edge; it can sharpen both straight and serrated blades. A few users complain that the slots themselves feel a little flimsy—they're most likely noticing the movement of the spring-loaded guides that hold your knife at the correct angle against the sharpening disks, a feature that experts love.
Users say there are two things to watch out for with this sharpener: First, stage/slot one removes a lot of steel (it has to, to convert a 20-degree edge to a 15-degree edge), so if you're dealing with knives that are still fairly sharp, you can probably skip straight to slots 2 and 3. Second, as with the 1520 AngleSelect, the newly sharpened knives can actually cut a groove into the plastic track beneath each slot if you're not careful. That said, users and experts agree that overall, the Chef's Choice 15 Trizor is easy to use. A lack of complaints about the noise levels makes us think you'll get the same quiet hum from this appliance as you'd expect from any Chef's Choice sharpener.
If you exclusively use knives with a 20-degree blade angle, you'll get similarly excellent results from the Chef's Choice 120 Diamond Hone EdgeSelect (Est. $150), a perennial winner in professional tests. This electric sharpener features three separate slots: one for rough grinding, one for finer honing and a third for stropping and polishing. It can be used with straight and serrated blades or chiseled (single-edge) blades and sporting knives.
The Chef's Choice 130 Professional Knife-Sharpening Station (Est. $160) delivers similar results, also for 20-degree blades, although instead of having rough/fine/stropping slots, it has a diamond abrasive in slot one, a sharpening steel in slot two, and the usual stropping disk in slot three. This model draws expert praise for its quiet performance, winning top marks in one test from a prominent test kitchen.
There's one last point that's worthy of note for all Chef's Choice sharpeners: The moving parts needed to create an electric sharpener usually create the potential for more to go wrong, and we do find a few complains about polishing disks that stop working. But we're impressed by just how few and far between they are, and found plenty of comments from users who say they're replacing a previous model that lasted for years.
For a totally different take on an electric knife sharpener, consider the Work Sharp Ken Onion Edition Knife and Tool Sharpener (Est. $130), named for knife-maker and inventor Ken Onion. This miniature belt grinder has five different 3/4-inch-wide abrasive belts, ranging from extra-coarse to ultra-fine, and a dial-adjust blade guide that can create edge bevels from 15 to 30 degrees. The most abrasive belt is reserved for sharpening tools like lawnmower blades, and shouldn't be used on kitchen knives; it'll remove too much steel.
John B. Holbrook, II, a professional photographer and knife enthusiast at ThruMyLens.org, writes on his blog that changing abrasive belts on the Work Sharp Ken Onion is quick and easy, with no special tools needed. The Work Sharp Ken Onion edition sharpener also has a variable-speed trigger control, which makes it easy to do a precise job, especially when you're first starting out.
As you might expect, the Work Sharp Ken Onion sharpener is fairly loud. You can speak normally and still be heard while using it, but probably wouldn't want to hold a conversation while the motor is running. As long as you keep a firm hold on the knife handle it's quite safe to use; the blade guides that hold your knife at the proper angle against the belt also double as protectors for your fingers. Lefties might have a harder time with this model, though, because it requires you to guide the knife with your right hand only while your left hand steadies the grinder and controls the speed.
A few users do say they can buy a wider, taller belt sander and abrasive belts for much less -- but most love the results they get from this sharpener, and feel like they're getting the best possible combination of an "old school" sharpening technique with a few modern touches to help keep both their blade and their fingers safe.