How to Sharpen a Serrated Knife

Serrated knives can and should be sharpened, but they don’t need it very often.

• A serrated knife’s pointed teeth do most of the work.
• Less friction means the blade stays sharper longer.
• The characteristics that keep them sharper also make serrated knives more difficult to resharpen.    

Your serrated knife has an interesting trick up its proverbial sleeve. It can go for years without being honed or sharpened. There’s no way its more popular friend, the chef’s knife, could get away with that.

Serrated knives have a unique design that helps them carry on with the solemn duty of cutting through crusty French bread without smooshing the soft inside. It’s something this type of knife can accomplish because it really isn’t like any other knife you have in the kitchen. Its blade edge works like a hand saw. The teeth catch and then rip through hard exteriors to reach and slide smoothly through softer interiors. If you’ve owned a serrated knife for more than a couple years, it may not have a very sharp edge anymore. It’s just deceptively efficient.

Sharp but Not Sharp

Serrated knives are the only piece of kitchen cutlery that will still work adequately when the blades are dull. The serrated edge of the knife owes its slicing ability to more than just sharpness.

The high points of the serrations come into contact with what you’re cutting first. These points apply higher pressure to the material than a non-serrated blade. The high points are able to puncture the surface. It’s why a serrated knife will grab and slice through the skin of a tomato, yet a tomato skin can resist all but the sharpest of non-serrated blades.

How long can a quality serrated knife go without sharpening? When properly used, they rarely require sharpening because of their construction, and they certainly don’t need the regular maintenance that the non-serrated blade of your chef’s knife calls for. A serrated knife will perform well for years — especially if you only end up using it as a bread knife.

Sharper Is Better

Sharpening a serrated knife is not as easy as returning the razor edge to your chef’s knife.

People unfamiliar with how to sharpen them — when it’s finally time — are guided by the misconception that it’s better to buy an inexpensive and low-quality serrated knife, and just toss it in the garbage when it obviously isn’t doing the job anymore.

Sidestep this disposable approach. Buy a quality serrated knife made of high-carbon steel. It’ll reward you with better edge retention, meaning it’ll need sharpening less often than the cheap ones you’ll have to regularly replace. It’ll take even longer — years — before you’ll have to sharpen the serrated blade.  

A serrated knife probably isn’t going to be used as much as the kitchen workhorses you have, such as your chef’s knife or paring knife. The serrations help protect the sharp edges residing in the gullets between the points, which don’t make full contact with the cutting board. For perspective, think of how many times the edge of your chef’s knife meets up with the cutting board.

The recessed part of the serrations are chisel ground into the blade. This means that the back side of the blade is flat, and the serrations are ground at an angle — just like a chisel. Over time, these chiseled edges will become dull, especially the high points that make first contact. The knife will still cut because the serrated edge can still catch and rip through the surface. Plus, the recessed gullets dull slower. You’ll have to press a lot harder, though, with a serrated knife that needs sharpening. You might not notice the difference until you resharpen the blade.

A quality serrated knife will continue to perform after years of use — but have you noticed lately that it’s not easy to get those beautifully symmetrical bread slices? And yes, now that you mention it, there are more crumbs and food morsels left on the cutting board than there used to be. These are signs that it’s time to sharpen this essential kitchen knife so that it will do a better job.

Sharpening your serrated knife will reduce the amount of pressure you put on the knife to get the teeth to catch and rip through the surface. Cut a few slices from a crusty loaf of bread with a dull serrated knife. Then sharpen the knife. You’ll see a dramatic reduction in crumbs.

You can do it yourself with the right tools, and it’s not a difficult task if you have a quality knife that was manufactured with the intent to be re-sharpened rather than discarded.

How Do You Sharpen a Serrated Knife?

Electric knife sharpeners may not work on serrated blades.

Sharpening a serrated knife is not as easy as returning the razor sharp edge to your chef’s knife. Many people prefer to have serrated knife sharpening done by a professional. At Misen, we sharpen the knives you buy from us for free.

One of the reasons why people prefer to have someone else sharpen a serrated knife is because the best method requires each serration to be sharpened separately. Let’s use our knife as an example. It features 33 serrations — not something you’ll whip through in just a couple of minutes.

Do you have an electric knife sharpener? It may have a slot specifically designated for serrated knives. However, lower end sharpeners likely won’t feature this option. Some motorized sharpeners will only touch the tip of the serrations. They could also damage the bevel by sharpening both sides of the blade with the fixed angle of the internal grinding disks.

Deluxe electric sharpeners use sharpening surfaces mounted on spring-action bars that conform to the shape and angle of a serrated blade, but even a high-end electric knife sharpener may have trouble reaching the entire surface of the concave gullets. There is no such thing as an automatic serrated knife sharpener. A manual approach will give you better results.

Do It Yourself

The right tool for manually sharpening your serrated knife is a ceramic honing rod. It’s also called a sharpening rod, and this can be confusing. A ceramic honing rod is harder than a steel honing rod, so the ceramic will remove some of the material from the blade’s edge, which has a sharpening effect. The shape of the rod is designed to fit inside the serrations of the blade. You’ll use it to sharpen the knife, tooth by tooth.

Start at the back end of the knife. Place the ceramic sharpening rod in the serrated grove, which is also known as the gullet. Position the rod so it matches the beveled angle of the chiseled cut you see in the gullet. Finding this angle isn’t difficult because the gullets of a serrated knife make the bevel easier to see. If you hold the sharpening rod flush with the bevel, you’ll automatically have the correct angle.

Slide the rod through the gullet toward the edge of the blade that does the cutting. Do this for each gullet. It should only take a few passes for each one. Resharpening the gullets with a honing rod also helps to reestablish sharp tips on the teeth. That’s important because the teeth make the initial entry into the material and begin the cut.

The Final Step

Once you’ve used the ceramic rod to sharpen each gullet, it’s time to turn over the knife for the last step. Sharpening a knife removes minute amounts of steel. Sometimes these remain partially attached to the blade and are known as burrs. You’ll be able to feel them if you gently run your finger along the backside of the blade. (Remember that on most serrated knives, this side is flat.) You’re sharpening it if you feel these burs. You’ve used the ceramic to draw metal up and over the edge of the knife blade.

These burrs can be easily removed by moving the flat side of the knife across the surface of the fine-grit finishing stone of your sharpening stone set. There you go. You’ve sharpened one of the most useful and important knives in your kitchen.

Additional Ways to Sharpen a Serrated Knife

Sharpening a serrated knife isn’t difficult but you’ll want to set aside sufficient time. Many home cooks opt for some assistance in this area and purchase a sharpening system.

The sharpening is still done manually, but these devices hold a set of ceramic rods in a 40-degree V shape. All you have to do is keep the knife steady as you move it down the triangular rod. The ceramic rod will move between each gullet. You’ll use the other ceramic rod on the flat side to remove burrs. It’s a manual sharpener with helpful guidance.

Sooner or Later

Call it a bread knife, or call it a serrated knife — just don’t call it un-sharpenable. A quality serrated knife can be sharpened because it was crafted from stronger steel and designed to be maintained instead of thrown away. When the time comes, it’ll be better for you to sharpen it yourself or send it out for professional sharpening. That way, you can hang on to your trusty knife for a long time to come.