Can You Sharpen a Serrated Knife?

There is a fact that gets repeated in kitchens, hardware stores and comment sections with total confidence:

"You can't sharpen a serrated knife. Just buy a new one."

It sounds right. It has the clean, satisfying shape of a real fact.

It's also mostly wrong, and it has sold a truly impressive number of replacement bread knives.

First, what a serrated edge actually is

A straight-edge knife is one long, thin ramp of metal. Simple. Boring. Great at slicing an onion.

A serrated knife gave up on being one blade and decided to be a committee.

Each one of those little scallops is its own small, curved cutting edge. The pointy bits between them are just the parts that grab onto whatever you're cutting so it can't slide away.

That's why a bread knife works on a crusty loaf and a tomato: the teeth bite through the tough outside before the soft inside has time to get squashed.

It's also why sharpening one is a different job. You're not sharpening an edge. You're sharpening twenty of them, one at a time, each one a different little curve.

So why does everybody say you can't?

Because you mostly can't, at home, with the stuff you own.

A honing steel does nothing for serrations. A pull-through gadget will happily grind the teeth right off and hand you back a sad, wavy butter knife. A flat whetstone only touches the pointy bits and skips every scallop, which is the opposite of helpful.

Sharpening serrations properly takes a tapered round abrasive that fits inside each scallop, worked at the original angle, scallop by scallop, without touching the flat side. That's a specific tool and a lot of patience, which is a polite way of saying it's a job for someone who does it all day.

The one question that decides it: one side, or two?

Here's the part nobody tells you, and it's the whole ballgame.

Most serrated knives are ground on one side only. One face is dead flat; all the shaping happens on the other. That flat face is a reference surface, which means the teeth can be rebuilt over and over without the edge wandering off.

Some serrated knives are ground on both sides, with teeth cut into both faces. Those can't be brought back the same way. Once they're gone, they're gone.

We sharpen serrated knives ground on one side. We don't sharpen serrations ground on both sides.

That's not us being picky. It's us not charging you to ruin your knife.

How to check your own knife in four seconds

1. Hold the blade with the edge facing away from you, flat on the counter.
2. Look at the side facing up. Scallops? Good.
3. Flip it over.
4. If the second side is smooth and flat, you're in business. If it has its own set of scallops, that one's a both-sides knife.

Most bread knives, most serrated utility knives and a lot of serrated steak knives are one-sided. If you're squinting at it and still can't tell, bring it by. We'll look at it for free and tell you straight.

Your bread knife is duller than you think

Serrated knives are sneaky. A straight edge tells you it's dull almost immediately. A serrated edge hides it for ages, because the teeth keep grabbing even after they've gone round and soft.

So the knife doesn't gradually get worse. It feels fine, fine, fine, and then one day it's smearing the tomato instead of cutting it and you can't remember when that started.

Signs yours has gone over the cliff:

• It tears bread instead of slicing it, and the loaf ends up squashed
• It slides across a tomato skin before it bites
• The tips of the teeth look rounded and shiny instead of pointed
• You've started sawing much harder than you used to, and calling it technique

What not to do in the meantime

• Don't run it on a honing steel. It does nothing useful and chews the tips. (If you want the real story on steels, we wrote a whole thing about honing.)
• Don't put it through a pull-through sharpener. That's the one that actually kills knives.
• Don't use it as a saw on frozen food. It looks like a saw. It is not a saw.
• Don't put it in the dishwasher. We say this about every knife and we will keep saying it.

What it costs to have us do it

Serrated knives are the same price as everything else. No serration surcharge, no drama.

• Drop-off: $8 a knife at our Flower Mound shop, 2809 Justin Rd, Unit A/B, Flower Mound, TX 75028. In before noon and it's usually ready the same day. How drop-off works.
• At-home: $35 for the trip plus $8 a knife, anywhere on our DFW and Austin routes. Book an at-home visit.
• Restaurants: your bread and serrated knives go in the pile with everything else on your weekly route stop.

And if it turns out yours is a both-sides knife, we'll hand it back and tell you so instead of taking your money. That is a much better conversation than the one where we charge you for it.

Cutco owners: your Double-D knives are their own special situation, and we cover them in the Cutco post. Short version: bring one in and we'll check it.

Restaurants: get startedHome cooks: book sharpening

Questions