How to Sharpen Your Kitchen Knives, According to Experts

There’s room to disagree about the essential cooking tools needed to prepare food at home, but there’s no question that owning at least one or two good knives is fundamental. But how good is your good knife if it’s dull? We’ve tested dozens of knives of varying styles and price points to help any home cook make informed purchases — but once you possess the perfect knife, how do you care for it? 

Many American homes turn to either an electric or manual sharpener, which works by having the knife inserted into it. While both products interface with the user differently, they function similarly. Whether manual or electric, you’ll want to be able to sharpen your knives with increasing nuance as your skills evolve.

John Somerall, Food & Wine's Editorial Project Manager of Food Research and Testing, is a classically trained chef with a passion for knives who has worked as a recipe tester and developer. He says, “The best way to sharpen knives at home is by using a method you’re familiar and comfortable with. Consider the amount of time and effort you want to devote to sharpening your knives and choose a suitable method for you.”

As for the correct cadence of sharpening, Somerall suggests that knife sharpening is less about a schedule and more about practice, beginning with inspecting our knives—or knife set—with frequency and looking at the blade's edge under a light. 

“If you work with your knives often, it becomes easier to notice when a knife becomes dull," he says. "You can look for micro-chipping or micro-serrations, though the most practical way of determining when it’s time to sharpen a knife is when it’s no longer working as well as it should. If you can’t easily cut through the skin of a tomato or bell pepper on the first try, it’s probably time to sharpen your knives.”

Equipment You'll Need

Manual Sharpener

After putting countless knife sharpeners through a set of tests, the Chef's Choice ProntoPro Knife Sharpener emerged as our favorite manual option — a versatile solution with a three-stage sharpener that works on both straight-edged and serrated blades.

We also love the Longzon 4-in-1 Sharpener for a less expensive option. It performed well during our tests, and the pull-through design means you can also sharpen your kitchen shears, which is a great perk.

Electric Sharpener

For fans of electric sharpeners, the Wusthof Easy Edge Electric Sharpener is our top pick. Three settings allow you to shape, sharpen, and refine your knife with one tool and the push of a button. We also appreciate its non-slip base for added safety.

For a budget pick, we think the Mueller Professional Electric Knife Sharpener offers incredible value. During our testing, it kept up with its pricier competition, and the user is able to choose between coarse and fine grit types.

How to Sharpening Your Knives with an Electric and Manual Sharpener

To use a manual sharpener:

1. Settle the knife into the coarse slot of the sharpener. Pull your knife through slowly and with even pressure.

2. Repeat this step three to six times.

3. Settle the knife into the fine slot of the sharpener. Pull through slowly and with even pressure once or twice.

To use an electric sharpener:

1. An electric sharpener reduces the physical effort of manually sharpening a knife. Review the knife sharpener's instruction manual carefully before beginning. 

2. Settle the knife into the coarse slot and slowly pull it through. The machine will do the heavy lifting.

3. Switch sides. Repeat the same motion on the other face of the blade.

4. Repeat this series of steps three to six times.

5. Using the finer slot, repeat steps one through three.

“Make sure you’re using a smooth, controlled motion as you pull the knife through a sharpener," shares Somerall. "It’s easy for beginners to over-sharpen their knives when using an electric sharpener. Remember that regularly sharpening your knives will extend their longevity, but over-sharpening them can have negative results and reduce their lifespan.”

Frequently Asked Questions

How do you use a whetstone?

Though requiring more practice and precision, a whetstone (or sharpening stone) is often recommended by professionals because it removes the least amount of material from the blade.

To use a whetstone, first submerge your stone in water for an hour. Place your stone on a towel over a cutting board or stable surface. (You’ll also want to keep a dish of water nearby to keep the stone wet as your work.) If your whetstone has a coarse and fine side, begin with the coarse side. Hold the knife with the handle in your dominant hand. Place the heel of your knife on the far edge of the stone, holding the blade at the desired angle (using an angle guide if needed). Applying even pressure, slowly pull the knife over the stone toward you. The blade should move smoothly across the stone. Lift the knife, reset the heel at the top of the stone, and repeat. Repeat as few as ten times and as many as 50. As you work, the water will begin to turn cloudy. This gritty water helps your knife become sharper with each stroke. Continue to apply water from time to time; you want it to be runny. Turn the knife over and repeat as many strokes as you did on the first side. When finished, allow your whetstone to dry on a rack in the open air for at least 24 hours with the towel.

To learn more about how to use a whetstone, follow our guide here.

How do you get rust off a knife?

If there’s a lot of corrosion, you can soak rusty knives in a bowl of white vinegar overnight (up to 24 hours). Then, remove them from the vinegar, and scrub the rust off with steel wool, a scouring pad, or a wire brush.

How do you sharpen a ceramic knife?

“Something to remember when sharpening ceramic knives is their lack of pliability," says Somerall. "Ceramic knives, typically made of zirconia (zirconium oxide), are much harder than stainless or carbon steel knives. They are great at retaining a sharp edge over a long period of time because they are so hard, but their hardness also makes them more brittle than stainless or carbon steel knives. When sharpening a ceramic knife, remember how much pressure you're applying to the face of the blade and where the pressure or force is being applied."

Because ceramic knives are not as pliable or flexible as stainless or carbon steel knives, it is much easier to chip or break the blade if too much force is applied, causing the blade to flex. For this reason, Somerall recommends using a whetstone.

"Use two hands to sharpen a ceramic knife when using a whetstone," he says. "A diamond stone is better suited for sharpening ceramic knives as diamond stones are harder and make the sharpening process more efficient. Because ceramic knives lack ductility, you won’t notice a burr developing as you sharpen the knife. Instead, you’ll need to rely more on your technique and the final grit associated with your tools to sharpen the knife effectively.”

Our Expertise

Christa Glennie has been a freelance writer and food editor for nearly 20 years. She is also the author of two cookbooks and specializes in food and drink trends, agriculture, the regional foodways of Western New York, and the restaurant business. Her respect for simplicity and uncluttered counters in the kitchen ultimately fuels a desire to find and own well-designed, multi-purpose, best-in-class kitchen tools. For this piece, she spoke with John Somerall, a chef, recipe tester, and knife expert.