Like deep-cleaning your refrigerator or scheduling a dentist appointment, knife sharpening is one of those chores many people avoid until it’s absolutely necessary. You might see someone offering the service at a farmer’s market or hardware store, but professional sharpening can be pricey. And let’s be honest—isn’t it easier and cheaper to just press a little harder when cutting that onion?
But dull knives are more than a kitchen annoyance—they’re dangerous. A dull blade requires extra force and is harder to control, increasing the risk of slippage and injury.
The good news? Sharpening at home is more doable than ever and it’s often better for your knives. Professional services frequently use belt grinders spinning at over 1,000 RPM, which can strip away too much steel, weakening your blade and causing it to dull faster.
A new wave of home sharpening tools makes it easy to keep your blades in top shape. From manual pull-through sharpeners to electric models with fine-grained diamond grinding wheels, these tools let you restore your knife’s edge in the privacy and safety of your own messy kitchen.
For home chefs, testing sites like Wirecutter and Food & Wine often recommend the Zwilling J.A. Henckels 4-Stage Pull-Through Sharpener—a simple and affordable entry-level option. For a step up, the Chef’sChoice 1520 and Chef’sChoice Trizor 15XV are popular electric models that are fast, reliable, and easy to use. And then there’s the Tumbler Roller, a newer sharpener with a diamond disc and magnetic knife holder that’s as stylish as it is functional.
For those seeking a more professional edge, the Tormek T1 is gaining attention among knife geeks. Designed by the iconic Swedish brand known for its pro sharpening systems, the T1 is their first home-use model. It operates at a slow, knife-friendly 100–120 RPM, using diamond wheels to maintain precision without overheating or removing too much steel.
The T-1 also has an angle guide with a needle that shows the exact angle for sharpening your kitchen knife. It’s a significant upgrade from fixed-angle pull-through sharpeners and bridges the gap between consumer convenience and professional results.
To learn more about the art of home knife sharpening, I spoke with Karl Frentz from Tormek about how to keep blades sharp without breaking the bank—or risking injury. Here’s what he had to say:
David Hochman: Why is professional knife sharpening so expensive?
Karl Frentz: Operational and overhead costs are a big part of it. People have years of experience and use whetstones and other expensive machines. They want to be paid for their time, understandably. But you have to be careful. Many sharpening services use belt grinders spinning at around 1,000 RPM. That removes a lot of steel, which can weaken the knife and make it dull faster. In some cases, you’re actually paying for a service that can shorten your knife’s lifespan.
David Hochman: In movies, you see people rubbing knives together to sharpen them, or sometimes using those rods. What’s the deal with that?
Karl Frentz: The rod you see is for honing, not sharpening. It removes burrs but doesn’t restore sharpness. The problem with honing rods is inconsistency—you can’t ensure the angle is precise. As for rubbing knives together, that’s purely for show. It might sharpen slightly, like using the bottom of a ceramic cup, but it’s not effective. A honing steel must be significantly harder than the blade of a knife, so two knives together generally won’t do the job.
David Hochman: What are some common myths or mistakes about knife sharpening at home?
Karl Frentz: Great question. A big issue in the U.S. is that people simply don’t sharpen their own knives or think they can. This might sound crazy but when their knives go dull, many people think they need to toss them and buy new ones. But if you invest in good knives and maintain them, they can last a lifetime. Whatever you use, it should involve minimal steel removal, so your knives retain their lifespan even with regular sharpening.
David Hochman: What about the angle of sharpening? How do you figure that out?
Karl Frentz: A: If you have the manufacturer’s specs, that’s the easiest way—most Western knives are set at 15–20 degrees per side, and Japanese knives are around 10–15 degrees. If you’re not sure, try the marker trick: draw a line along the bevel with a marker, then make one sharpening pass at an angle like 15 or 20 degrees. Check if the marker is fully removed—if not, adjust the angle until it is.
If you don’t have details, 15 degrees is a good middle ground for sharpness and durability. The thing to remember is that thinner angles, from 10 to 15 degrees for sushi knives, are sharper but dull faster, while wider angles, from 20 to 25 degrees, are sturdier but less sharp. In short, it’s about testing and tweaking until it feels right for the knife’s purpose. Some people keep a cheat sheet—“My chef’s knife is 15 degrees, my butcher’s knife is 20”—to simplify future sharpening.
David Hochman: Dumb question: How do you know when a knife is sharp enough?
Karl Frentz: Not dumb, actually. There are a few ways to test. Hold the knife up to a bright light—if you see tiny dots reflecting, those are dull spots. You can also run the blade lightly along your finger, carefully, to feel for bumps—smoothness indicates sharpness. Another method is the paper test. A sharp knife should glide smoothly through paper without catching or tearing.
David Hochman: Can you sharpen serrated knives?
Karl Frentz: It’s trickier. To sharpen a serrated knife, you sharpen only half—the flat side, not the serrated side. It’s tough at home for most people, so I don’t recommend it. It’s easy to wear down the teeth. If it’s really needed, you can do a single pass at a wide angle, like 18 degrees, but do it sparingly.
David Hochman: Anything else you’d like to share?
Karl Frentz: Sharpening knives may look intimidating at first, but there are great resources online to guide you and companies like ours have customer support to help. Once you try it, you’ll see how straightforward it is. Also, it’s sustainable—you’re preserving knives rather than replacing them—and it’s fun to do.
This interview has been edited and condensed (or perhaps I should say sliced and diced) for clarity.
