In every cooking class that I teach, knife sharpening is the first lesson my students learn. Dull knives are inefficient and dangerous – a dull blade can slide right off the curvature of an onion into the flesh of the hand holding it.
At the Drexel Food Lab, where I’m a certified research chef and culinary educator, we use a Tormek T2 Pro Kitchen Knife Sharpener, donated by the company, to sharpen our knives. It is a dream piece of equipment that can sharpen any knife we throw at it, from a pile of our classes’ cheap stainless steel Dexter kitchen knives to a high-end carbon steel Japanese slicer for our instructors’ use.
But at nearly $900 and 14lbs, the T2 is overkill if you’re not running a professional kitchen. It’s driving a Lamborghini in stop-and-go city traffic. For easy home use, I recommend the Horl 3, a simple-to-learn rolling knife sharpener with a stand that holds the knife in place at the optimal angle. Co-founder Otmar Horl, an engineer, together with his son, Timo, a graphic designer and barbecue enthusiast, designed the first rolling knife sharpening system that became the Horl 3 in the basement of their family home, where they produced the first 200 units by hand.
A decent whetstone can be found for under $10, so no one needs a Horl 3. But the speed, smooth action and attractive gadgetry makes it worth it for the serious home cook.
How do you properly sharpen a knife?
As a young cook, one of the first things I learned was geometry. To properly sharpen a knife on a whetstone, your blade must meet the surface of that stone at an approximately 15-degree angle. I still teach this to my students today: the blade perpendicular to the stone is 90 degrees. Tilt the knife in either direction about halfway and that’s 45 degrees. Eyeball one-third of that and you’ll reach the correct angle. Two pennies slipped under the blade (if you can find a penny these days) will also remind you to maintain the correct angle. After you’ve nailed the angle, pay attention to the sound. A blade sliding across a whetstone properly will “sing.” If the angle is too shallow, you’ll hear a cringey mechanical grinding; fingernails on a chalkboard. If the angle is too deep, you’ll feel it – a halting, stop and start ba-dump-ba-dump as the blade skips rather than slides. (I’ve heard it all.) With practice, whetstone sharpening is meditative, honing the mind of the pre-shift cook, along with the blade.
How does a knife actually sharpen?
When a knife dulls, the uniformly sharp angular edge becomes flattened, bent and bruised at various points, sending everything out of alignment. The goal of knife sharpening is to grind down the microscopic bits of metal that have formed over time and to reshape the original angle of the sharp blade (hence the constant emphasis on angles when discussing knife sharpening). Since steel is quite hard, a diamond wheel (harder than steel) or hard stone like novaculite is used to grind the metal of the blade. As the metal grinds, bits of metal called the “burr” develop along the opposite edge. Smoother stones can be used later in the process to remove the burr and smooth the blade. The last step, honing, doesn’t sharpen. When you run a knife up and down a magnetized steel (or increasingly a ceramic rod), all you’re doing is realigning and straightening the newly ground metal bits, which helps maintain the sharp edge of the blade.
How does the Horl 3 work?
The Horl 3 takes the same principles as a motorized grinder such as the Tormek and compresses them to a hand-held two-piece kit. A wooden block with strong magnets on either end – the “angle support” – allows you to attach the knife, blade-side up and hold it in place at a 20 degree or 15 degree angle. The sharpener itself is a wooden cylinder, like a little rolling pin, about 2in in diameter, with a twist-and-lock removable disk on each side – a diamond disk for sharpening and a ceramic disk for honing. Additional discs and gradations can be purchased if needed; I didn’t find that they were.
Using the Horl 3 was easy on the first attempt. First mark the edge of the blade you intend to sharpen with a felt permanent marker to serve as a visual guide. When the mark is no longer visible, the blade is sufficiently ground, a helpful tool to make sure you sharpened the entire blade. Next, attach the knife to the angle support at your preferred preset angle with the blade up, spine down. Roll the cutting blade up and down each side of the blade multiple times with a motion similar to rolling a paint roller. Rotate the Horl 3 to the honing disk and repeat. The manual advises a final step of using a leather strop (not included) to remove any remaining burr, but a steel one works just fine. Once my knife was sharpened, my towel was marked with the tell-tale sign of a successful sharpening: gray metal dust.
What we love
Using the Horl is, simply put, fun – more fun than preparing and using a whetstone. Timo Horl said: “At expos, when you attach the knife to the magnet and it makes the sound, people’s eyes get big. It seems easy but it’s also exciting.”
A sharpener is only worth its weight if it can do its job well. To test how well the sharpener worked, I used the same method I teach my students. First, grab a 8.5in x 11in sheet of printer paper by the corner and try to cut through the paper: if the knife slices through, it is sufficiently sharp. If the paper bounces off the knife, go back to the sharpener and spend more time to get it right. The Horl 3 yielded a knife that consistently cut through paper on the first attempt. With whetstone sharpening, I often have to send students back to the stone to work on their knives more.
Another true test is the tomato. A dull knife will be stymied by the tomato skin, slicing and smashing the fruit simultaneously. A sharp knife will move effortlessly through the skin. The knives sharpened by Horl 3 passed the test on the first attempt as well.
Apart from how well it works, the Horl 3 is compact enough to fit in a utensil drawer, but it’s attractive enough to leave out on the counter, too. Excellent videos and a simple illustrated operating guide help the Horl 3 deliver on its promise to “achieve impressive sharpness without prior knowledge”.
What we didn’t love
Knife nerds who want more control may be frustrated by being limited to 15 or 20 degrees. (The company anticipated this limitation – the Horl 3 Pro offers six angles to choose from, ranging from 10 degrees to 25 degrees.) My other frustration was that the easily interchangeable discs, while attractive as a feature, popped off occasionally when in use. While not a safety or quality concern, I expected more sturdiness once the discs were locked in place.
Is it worth it?
I recently spoke with a prominent food editor and told her about my experiences with Horl 3. She confessed to being intimidated by freehand whetstone sharpening and lets her knives dull to disuse instead, adding new sharp knives to her collection. This is the customer the Horl 3 will save: seconds to learn, minutes to use and allowing good knives to last decades or longer. I found the ease of use and compact size had me sharpening my home knives more than usual – making them safer and more efficient – even after my testing for this article was complete.
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