There’s nothing worse than a dull knife. First of all, a dull blade edge is MUCH more dangerous than a properly sharpened blade. That’s because instead of the knife doing the work and the cutting edge sliding cleanly through whatever you are cutting, you need to push harder to get the blade through. Between the extra pressure and the chance of the blade slipping off what you are cutting instead of cutting through it, a nasty accident is much more likely when your knives are dull.
There’s also no reason to have a dull knife. There are hundreds of different sharpeners on the market that are designed for everyone from first-time users to chefs or even custom knife makers. So take some time to check out some of the many online knife sharpener reviews.
Every cook should have a quality knife sharpener and, with research and some practice, you’ll soon be keeping the most important tool in the kitchen in top shape, making your food look better and keeping you out of the local emergency room or urgent care.
Sharpening vs. Honing: What’s the difference?
When talking about making knives sharper and safer to use, many people mention “sharpening” and "honing” as if they are the same thing. They are two different processes, both of which are needed to keep your knives in top condition.
When you are sharpening a blade, you are peeling off tiny bits of metal against an abrasive surface, making that part of the blade thinner, and creating a precise angle on the edge of the blade. Essentially, you are taking a piece of metal with a dull edge that is shaped sort of like the letter U and grinding off material to shape it more like a V. When the point of the V at the edge of a blade is precise and at the proper angle all the way along, that blade has been properly sharpened.
A honing rod, usually made out of steel, ceramic, or diamond, performs a more subtle re-shaping of your knives’ blades. Honing a blade pushes all the bits of steel along the edge so they are lined up in the same direction. Think of it as a little bit like combing your hair so that it lays down smoothly. While sometimes referred to as a sharpening steel, these tools won’t give your blade a sharp edge, but honing will refresh the edge between sharpenings, keeping your knives safe and easy to use.
Best Way to Sharpen Your Knife
A pull-through knife sharpener provides the best combination of ease of use, predictable and consistent results, and cost for the vast majority of casual cooks. There are two common designs for handheld manual pull-through knife sharpeners. One type consists of a flat-bottomed plastic or metal stand with a V-shaped cutout containing abrasive rods in the upright section. Most have a protected C-shaped handle you can wrap your fingers around, attached to a box-like section that holds from one to four abrasive rods set into precisely angled sharpening slots.
On a quality multi-slot, pull-through knife sharpener like the RAZORSHARP Knife Sharpener, those can range from sharpening (coarsest grit), to polishing (fine grit), to honing, each of which refines the edge of your blades in specific ways. Both the handle and the sharpening section should have durable, non-slip surfaces where they rest on the countertop. You do NOT want your sharpener moving while you are pulling a blade across it, and you don’t want to have to hold it down with a lot of force, either. A good-quality manual knife sharpener will have a solid no-slip handle and base and carefully engineered slots that control the angle of the blade's edge. The slots also hold various abrasive sharpening surfaces made of ceramic, metal, or a combination of materials. Some pull-through sharpeners work for both western-style and Asian-style knives by adding separate slots for the different blade angles.
Some models have an adjustment wheel that lets you change the angle for a particular sharpening slot. Others can only sharpen one type of blade, so be careful to select the right sharpener for your knife collection. Some manual pull-through sharpener models include a sharpener for your scissors.
The best pull-through knife sharpeners will have a sturdy sharpening blade that will last a long time. A good pull-through knife sharpener will also be comfortable to hold and easy to control. When shopping for a knife sharpener, you should ideally have the chance to hold the product in your hands and test it out. However, if you have to shop for a knife sharpener online, be sure to thoroughly read the reviews and see if there are any articles about the product written by an objective expert.
When you get your new sharpener, it’s a good idea to practice first on a less-expensive knife, just to get the feel for how the blade travels across the abrasive and the motion of your arm as you draw the blade through the slot. That will help you get the feel needed to put a consistent and correct angle all the way down your blades.
The basic steps are the same, whatever model you choose.
- Test the blade by slicing through a sheet of paper or trying to cut a ripe tomato.
- Choose the right angle and select either the coarse (sharpen) or fine (polish) setting, depending on the type of blade and how dull it is.
- Place the “heel” of the blade closest to the handle into the Coarse sharpening slot.
- Pull the blade smoothly across the abrasive sharpening tips while applying steady but gentle pressure.
- If the blade is curved, keep the metal pressed evenly against the abrasive by raising and lowering the handle as you go to adjust the angle.
- When your blade is nicely sharpened, run it across the Fine setting a couple of times to give the edge a perfect finish.
- Rinse your knife and wipe the blade clean and dry.
- Then, each time you are going to use it, run it over a sharpening steel (also called a honing rod) to ensure it is ready to cut smoothly.
Other Ways to Sharpen Your Knives
We’ve been sharpening blades a lot longer than we’ve had industrial designers thinking about function AND looking good on your kitchen counter.
Humans have been using rocks to sharpen sticks of all kinds for as long as people have been poking or slashing at things. The oldest way is still used by many craftspeople and chefs, and it takes time to learn. The refined, modern version of those rocks is called a whetstone or sharpening stone.
Whetstones are made of very specific and consistent mineral materials, either natural or engineered stone. They are often two-sided, with different levels of coarseness in the stone’s grit, making one side rougher than the other. Many sets come with multiple double-sided stones. That ends up about the size of a brick in some cases. The big challenge with using a sharpening stone, for most folks, is that you need to learn and apply precise muscle memory and learn about how a blade feels in your hand as it sharpens. Without a guide to set the angle, most whetstone newbies put too much or too little of an angle on the blade and don’t apply the same edge all the way down the blade. It is a bit of an art form, and it is easy to end up with a duller blade than you started with.
Workshop enthusiasts might choose rotary grinding wheels, which require similar practice to using a whetstone, if not more. The biggest difference is that you can wreck a blade in one go on a grinder, and your knives will grind away to slivers much quicker than any other method. We didn’t give any of these a whirl for this post, given how difficult they are to use for the average consumer.
Electric Knife Sharpeners
A counter-top electric sharpener operates on the same (but scaled-down) principle as a grindstone. An electric motor spins abrasives at the bottom of angled slots while you draw the blade between them. Again, because the motor determines how much steel is removed, it is easier to damage and wear out blades using electric sharpeners than manual pull-through ones. The motors make the process a little quicker than with a manual, but electric knife sharpeners also tend to take up more space than manual models due to the motor housing and the sharpening slots.
More expensive models, like the Chef’s Choice range, give you the most options (6 slots on the Trizor XV). But we also liked the Presto 08810 Professional Electric Knife Sharpener, which handles a wide variety of blades and does a great job with just a slight amount of pressure.
Commonly Asked Questions About Sharpening Knives
Can you sharpen a serrated knife?
A serrated blade needs a different sharpening tool and technique than straight-edged blades, but they can be given a fresh edge if you have the patience. Most serrated knife sharpeners are rods, similar to a smaller version of a sharpening steel or honing rod. They are tapered to fit different sized serrations (think of the difference between a serrated tomato knife and a bread knife, for example). In most cases, serrations are shaped differently on either side of the blade, as well, and it’s critical to use a sharpener only on the beveled side, where you can see there is an angle to the blade. Why will you need patience? Each of the serrations has to be individually, and identically, sharpened!
What angle to sharpen a knife
A 20° angle provides a great, long-lasting edge for most kitchen knives. It is the most commonly used angle for high-quality western-style blades. If you are a fan of Asian-style knives, like the santoku or a cleaver, you’ll be going for a finer edge and a smaller angle, typically about 15°. That also means that the edge is thinner on these knives, so extra care is needed when sharpening them and when using them.
For knives you’d typically use outdoors, like a clasp knife or hunting knife, most manufacturers recommend sharpening the knife blades to a 25° angle.
Can you sharpen scissors with a knife sharpener?
Scissors have a different edge profile that makes them unsuitable for sharpening using a pull-through sharpener’s knife sharpening slots. As noted, some pull-through sharpeners like the ones from RAZORSHARP include a purpose-made scissor sharpening slot. If the pull-through model you choose includes the scissor option, use it! Believe us, there’s nothing more satisfying than discovering that your scissors just slide through paper and cloth again, as cleanly as easily as when you bought them long ago.
Can you sharpen a ceramic knife with a steel?
Ceramic-bladed knives have become pretty common in kitchen stores, and they do have their fans. But it’s tricky to sharpen ceramic knives. That means a lot just get thrown away when they lose their edge, but that does take a while. Ceramic kitchen knives are also brittle, making it easy to snap them while sharpening the edge.
All sharpeners have to be harder than the blade you use them on, so they can grind away the edge of the blade. For ceramics, that means using a sharpener with a diamond abrasive.
Why is it necessary to sharpen a knife regularly?
As you use your kitchen knives to chop vegetables or cut up meat and bones, the metal edge slowly loses material and becomes pitted and nicked. Also, over time, the edge can bend over, creating a microscopic, dull U shape. The only way to restore the edge is to grind away some of the metal until you can restore the right thickness and the right angle.
What is the best knife sharpener for hunting knives?
Most folks who regularly sharpen hunting knives, machetes, or even hatchets, recommend using a sharpening stone like Smith’s TRI-HONE Sharpening Stones System. One caveat: the size of some of these whetstone systems makes them more practical for keeping in a shop or truck, but there are also several smaller sharpening stones for use in the field. For less experienced knife handlers, there are many manual and electric pull-through sharpeners designed specifically for hunting knives.
What is the best grit for sharpening knives?
Like so many things, the “best” grit depends on the knife it is used on. Generally speaking, sharpening abrasives range from very coarse grit, to take off a lot of metal on the first pass to extremely fine grit or even mirror finish. For most kitchen knives that haven’t suffered unusual damage to the blade edge, you’ll want to start with a medium-coarse grit and move down to medium-fine grit, which will give you an edge very similar to what the factory put on the blade originally.
How often should knives be sharpened?
For most home cooks, good quality stainless steel kitchen knives will retain an acceptable edge for about 3 to 6 months before they need a proper sharpening. In the meantime, you’ll want to hone the blades more frequently. For a carbon steel blade, you should hone it before each use. The other great reason to put your honing steel to work regularly is that it will tell you when your knife needs sharpening. A knife with a good edge will cut cleanly after it is honed. Once your honing steel stops bringing a blade back to safe, smooth cutting, it’s time to get out the sharpener.
Early Signs of a Knife Blade Going Dull
Ongoing use of any knife will certainly show wear and tear to the blade, but there are plenty of signs to be on the lookout for to know when your edge is beginning to underperform. Kitchen knives, in particular, can make preparing your meals a task if they are beginning to dull, and so it is essential to take note of the following:
It feels Dull
The blade feels dull to the touch. Sharp knives will have a distinct edge, but worn blades will allow you to press and slide your finger against them. Any blade that feels rounded off at the touch requires a good sharpening before use.
It Catches the Light
A blade that catches and reflects light is a visual sign that it is time to sharpen. You can perform this test by holding the edge straight and then slowly tilting it left to right. Any areas in which the light catches will be dull and need a touch-up.
It Doesn’t Pass the Fingernail Test
You can tap a knife against your fingernail's tip to test its sharpness. If the blade is sharp, it will bite into your nail. If not, it will deflect or slide away.
It Smashes Rather Than Slices
Simply using your knife for prep work in the kitchen is the quickest and easiest way to tell that it is dull. For example, while cutting tomatoes, if the blade is smashing rather than slicing, the knife is too dull for cutting.
Likewise, if it rolls or slides against what you are cutting, that is another good indicator that the quality has fallen. Knives that push down rather than slice straight through will always require sharpening.
Know When To Replace Your Knife
A knife of good quality can withstand years of usage. Through sharpening and proper care, you can prolong the life of any blade, but some situations call for a total replacement.
Chips or Cracks
There are visible chips in the blade. While some minor signs of damage can usually be repaired with patience and care, some more severe chips or deformities can make the edge unsafe to handle or make it perform poorly. Keep an eye on any small chips or cracks and make sure they do not expand, as this can affect the integrity of the blade itself and make it far less safe and reliable.
The tip of the blade is chipped or warped. Sometimes accidents cause lasting damage to an edge that cannot be repaired, requiring the knife to be replaced. Dropping a knife is the main culprit of tip breaking, and while a small break may not be so critical to the blade being used in the kitchen, it can still make getting a proper cut quite tricky in some cases.
Just as important as the blade is the handle itself; if broken, it can cause injury to your hands. Dropping a knife can cause a handle to crack or break off entirely. Overuse due to wear and tear, or a low-quality knife, can also face this issue sooner rather than later.
Cracked or broken handles can pinch fingers and palms while cutting; if it comes off entirely, the knife will be nearly impossible to use.
Loose rivets can undoubtedly cause issues on any blade. Rivets are responsible for keeping the edge intact; if they are loose or fall off, the blade will lack balance and stability. The rivets in kitchen knives also hold the handle in place, so without them, the edge would simply fall apart and expose the tang of the blade. In these situations, it is far easier to replace the knife.
The most direct indication by far is the sheer discomfort of a knife. If it feels odd in your hand, causes pain, or wears down your wrist during use, it may be best to seek out a blade that fits your hand better.
Not all knives are universal, so test out various blades before deciding what type and brand you prefer. Also, keep up to date on warranties through the manufacturer as broken handles or blade damage could mean getting a replacement at no charge.