What Causes a Knife to Get Dull?

If you have ever pulled your favorite kitchen knife from the drawer only to find that it could not slice through a tomato without smashing it, you are not alone. Even a good knife can lose its edge surprisingly quickly when it is subjected to everyday habits that are hard on the cutting edge.

As a professional sharpener at Sharp On Sight, I see this all the time. One of the most common things I hear is, “I just bought this knife and it’s already dull.”

Sometimes the steel and factory edge are part of the problem. But very often, the way a knife is used, washed, stored, and maintained is what shortens the life of the edge.

If you want to understand why some knives hold an edge longer than others, I go into that in more detail in my guide to blade steel and edge retention.

Here are some of the most common things that dull a knife quickly, why they damage the edge, and what you can do instead.

1. Cutting on Glass, Granite, Ceramic, or a Dinner Plate

This is one of the fastest ways to take the bite out of a sharp knife.

Glass cutting boards, granite countertops, ceramic plates, and similar hard surfaces offer very little give when the cutting edge makes contact with them. The edge of a knife is extremely thin, and repeated impact against a hard surface can roll, deform, or chip that edge.

A knife can still look perfectly fine while the very apex of the edge has already been damaged enough to make cutting noticeably harder.

What to do instead:

Use a quality wood cutting board. End grain maple, walnut, cherry, and other knife friendly woods provide some give under the blade and are much easier on a fine cutting edge.

If you care about keeping your knives sharp, your cutting surface should be considered part of your knife care routine.

2. Do Dishwashers Dull Knives?

Yes. Dishwashers can dull knives and cause other damage over time.

The biggest concern for the cutting edge is that a knife can move during the wash cycle and strike racks, dishes, or other utensils. That repeated contact can roll, chip, or damage the extremely thin edge.

Harsh detergents and prolonged moisture can also contribute to corrosion, particularly with carbon steel knives. Repeated dishwasher cycles may also damage wood and some other handle materials.

A dishwasher can contribute to:

• Premature edge dulling

• Microchipping or rolling of the cutting edge

• Corrosion, especially with carbon steel

• Damage to wood and some other handle materials

What to do instead:

Hand wash your knives with warm, soapy water and dry them immediately.

It takes less than a minute and eliminates one of the easiest ways to unnecessarily shorten the life of a sharp edge.

3. Can a Knife Block or Drawer Dull Your Knives?

A knife block is not automatically bad for your knives. Proper storage is actually one of the easiest ways to protect an edge.

The problem is unnecessary contact.

A knife stored loose in a drawer can slide into peelers, tongs, silverware, or other knives every time the drawer opens and closes. Those repeated impacts can damage the edge before the knife even reaches the cutting board.

A traditional knife block can also create unnecessary edge contact if the cutting edge is repeatedly dragged against the slot when the knife is inserted or removed.

What to do instead:

Use a knife block carefully, a magnetic knife strip, or a knife guard.

If you store knives in a drawer, individual edge guards are an inexpensive way to prevent the blades from banging into everything else in the drawer.

However you store them, the goal is simple: keep the cutting edge from repeatedly contacting hard objects.

4. Scraping Food Across the Cutting Board With the Edge

This is an extremely common habit.

You finish chopping an onion, turn the knife sideways, and use the cutting edge to scrape everything into a pan.

The problem is that a knife edge is designed primarily to handle forces moving into the edge. Dragging that extremely thin edge sideways across a cutting board places lateral stress on it and can contribute to rolling and premature dulling.

What to do instead:

Flip the knife over and use the spine to move food across the board.

Better yet, use a bench scraper.

That small change can prevent a lot of unnecessary wear.

5. Using a Chef Knife for the Wrong Job

A chef knife is versatile, but it is not a pry bar, screwdriver, cleaver, or multitool.

Using a chef knife to cut bone, twist through frozen food, crack hard shells, pry something apart, or open packaging can put forces on the blade and edge that it was never designed to handle.

Thin edged chef knives and many Japanese knives deserve particular care because their geometry is designed around cutting performance.

What to do instead:

Match the tool to the job.

Use a proper cleaver when the job calls for one. Use a paring knife for detailed work. Use a bench scraper to clear the cutting board. Use an actual tool when something needs to be pried open.

A knife will last much longer when you ask it to do the job it was designed to do.

6. Skipping Edge Maintenance

Every knife loses some cutting performance with use, but that does not always mean it needs a complete sharpening immediately.

A ceramic honing rod can be useful for refreshing an edge between full sharpenings. Unlike the common explanation that honing simply “realigns” an edge, ceramic is mildly abrasive and can remove a very small amount of steel while restoring some bite to the cutting edge.

It will not repair a badly worn, chipped, or completely dull knife, but it can be useful maintenance when the edge is beginning to lose some of its performance.

What to do instead:

I prefer a ceramic honing rod for routine kitchen knife maintenance.

Use it when you begin to notice the edge losing some bite rather than following an arbitrary schedule. Angle matters, and the appropriate angle depends on the knife and the edge geometry.

If you are not comfortable doing it yourself, ask me the next time you bring your knives in for sharpening and I can show you what I recommend for your knife.

7. How Often Should You Sharpen Your Knives?

There is no universal sharpening schedule.

How often a knife needs sharpening depends on:

• The steel

• Edge geometry

• How frequently the knife is used

• What you cut

• Your cutting surface

• How you store the knife

• How you maintain the edge

• How sharp you expect the knife to remain

A home cook who prepares a few meals each week may go many months between sharpenings. A heavily used kitchen knife may need attention much sooner.

Rather than automatically sharpening every three, six, or twelve months, pay attention to how the knife performs.

If routine edge maintenance no longer brings back the cutting performance you expect, it is probably time for sharpening.

Waiting until an edge is severely worn or damaged can also require considerably more work and material removal to restore proper geometry.

How to Keep a Knife Sharp Longer

A few simple habits can make a noticeable difference:

Use a quality wood cutting board.
Avoid glass, granite, ceramic, and dinner plates.

Hand wash and dry your knives.
Keep them out of the dishwasher.

Store knives so the edges are protected.
Avoid tossing bare knives into a drawer.

Use the spine or a bench scraper to move food.
Do not scrape the cutting edge sideways across the board.

Use the right knife for the job.
Do not pry, twist, or force a thin chef knife through something it was not designed to cut.

Maintain the edge before it becomes completely dull.
A ceramic honing rod can help maintain useful cutting performance between sharpenings.

None of these habits will keep a knife sharp forever.

Every knife eventually needs sharpening.

What Happens During Professional Knife Sharpening?

When a knife reaches the point where maintenance is no longer restoring the edge, sharpening removes steel to create a new cutting apex.

At Sharp On Sight, the process depends on the knife, its condition, the steel, and the type of edge being restored.

That can include:

• Edge profiling: Restoring or correcting the bevel geometry

• Abrasive progression: Using abrasives appropriate for the condition of the knife and the edge being created

• Deburring and finishing: Refining the cutting edge and removing the burr

• Leather stropping: Used where appropriate to refine and finish the edge

• Edge inspection: Checking the finished edge for consistency and cutting performance

The goal is not simply to make the smallest edge angle possible or polish every knife to a mirror finish.

The goal is a clean, consistent, sharp edge that makes sense for the knife and how it will actually be used.

How Do You Know When a Knife Needs Sharpening?

Your food will usually tell you.

If a knife that once sliced tomatoes cleanly now slides across the skin, if onions require noticeably more pressure, or if you find yourself forcing cuts that used to be effortless, the edge is losing performance.

You can also try a simple paper test.

A sharp kitchen knife should be able to slice through ordinary copy paper cleanly. If the edge catches, tears, or repeatedly skips across the paper, it may be time for maintenance or sharpening.

Do not focus only on whether the knife technically still cuts.

Pay attention to how much effort it takes to make the cut.

Frequently Asked Questions About Dull Knives

What dulls a knife the fastest?

Hard cutting surfaces are among the fastest ways to damage a fine kitchen knife edge. Glass, granite, ceramic, and dinner plates provide very little give and can quickly roll, deform, or chip the edge.

Improper use, such as scraping the cutting edge sideways across a board, cutting bone, or twisting a thin blade through hard or frozen food, can also damage an edge very quickly.

Do knives get dull in the dishwasher?

Yes. A dishwasher can contribute to dulling when the knife strikes racks, dishes, or utensils during the wash cycle. Detergents and moisture can also create problems for certain steels and handle materials.

Hand washing and immediately drying a kitchen knife is the better option.

Is a knife block bad for knives?

Not necessarily.

A knife block can provide good protection if it is used properly. Problems can occur when the cutting edge is repeatedly dragged against the slot or when the block is dirty or poorly suited to the knife.

Loose drawer storage is generally a much bigger concern because the edge can repeatedly strike other utensils.

Does stainless steel still get dull?

Absolutely.

“Stainless” describes the steel's resistance to corrosion. It does not mean the cutting edge stays sharp indefinitely.

Stainless knife steels can still wear, roll, chip, and lose cutting performance. Different steels simply do so at different rates.

How often should I sharpen my kitchen knives?

There is no single schedule that works for everyone.

Sharpen the knife when its cutting performance has deteriorated enough that normal maintenance no longer restores the edge you want. Steel, usage, cutting surface, storage, edge geometry, and personal expectations all affect how frequently that happens.

Even Serrated Knives Eventually Get Dull

Serrated knives may hold useful cutting performance for a long time, but they are not immune to edge wear.

They also require a different sharpening approach than a typical straight edged kitchen knife.

If you have ever wondered why so many sharpeners refuse to work on them, here is why serrated knives require a different approach to sharpening.

Sharp Habits Make a Sharp Kitchen

Most kitchen knife edge damage is preventable.

Use a good wood cutting board. Keep your knives out of the dishwasher. Store them properly. Do not scrape the cutting edge across the board. Use the right tool for tough jobs, and pay attention when the edge begins losing performance.

Those habits will not eliminate sharpening, but they can help you get much more useful cutting time from the edge you already have.

And when maintenance is no longer enough, that is when sharpening makes sense.

Sharp On Sight provides professional knife sharpening in Sun Prairie, Madison, and the surrounding Dane County area. I sharpen Western and Japanese kitchen knives, serrated knives, pocket knives, hunting knives, scissors, shears, and many other edged tools.

Need Your Knives Sharpened?

Visit me in Sun Prairie for live sharpening, or take a look at the current sharpening schedule and details.

Sharp knives work faster. So you can, too.