Knife sharpening stoneA knife doesn’t stay sharp forever, and you’ll notice the difference when it loses its edge.

  • Electric knife sharpening machines offer convenience.
  • Sharpening stones have a learning curve.
  • Sharpening stones can lengthen the lifespan of your knives.  

In a perfect world, everybody loves what we post on Instagram, dogs stay as cute as they were as puppies, and knives never get dull. Alas, even quality knives made of premium steel will eventually lose their cutting edge.

The good news is that there are a variety of ways to bring back that razor-sharp edge. Each technique falls into one of two basic camps: speed and convenience vs. do-it-yourself satisfaction

Why You Should Keep Your Knives Sharp

How you sharpen your knives is a personal preference, but why you should keep them sharp causes no disagreement. Dull knife blades are a safety hazard. A knife that’s lost its sharp edge will slip on food and increase your chances of injury. Few examples prove this better than trying to slice a tomato with a dull chef’s knife.

A dull knife increases the amount of time you spend preparing what you cook. Sharpening your knives makes you more efficient in the kitchen. And because a sharp knife makes more precise cuts, you’ll minimize food waste.

A dull knife will make your food appear … well, dull. A very sharp knife blade reduces the damage done at a cellular level as it cleanly slices through food. It decreases moisture loss, which accelerates oxidation. Chopped herbs wilt faster, and a sliced apple will turn brown more quickly.

It’s why sharpening is a skill you should learn — whether you do it with a knife sharpening machine or with knife sharpening stones. Here’s what you need to know about each method.

Knife Sharpening Machines

Knife sharpening stone: a tomato balanced on a knifeEven something as fragile as a tomato can resist a dull kitchen knife blade.

Electric or manual sharpening machines are advisable if you have little or no experience maintaining high quality cooking knives. The learning curve consists of reading short instructions and following the steps.

Electric Knife Sharpeners

These boxy electric sharpening devices feature a series of slots. A quality electric knife sharpener features small orbiting plates of abrasive material that are set at fixed grinding angles. Each slot features plates with different levels of abrasiveness.

The blade is sharpened as you pull it through the series of slots. The first slot will be the most abrasive. Think of the process as if you were sanding wood. You’d use coarse or more abrasive sandpaper to start and work your way to a fine grit to get the final, smooth surface. Pulling your knife through the slots of an electric knife sharpener restores the blade edge angle while sharpening so it slices cleanly through food.

Electric knife sharpeners are easy to use. You literally place them on a countertop, plug them in, and turn them on. Depending on the condition of your knife blade, you can be finished with a sharpening session in about 30 seconds — the time it takes to pull the blade through the standard three slots of the sharpening machine.

The downside of electric knife sharpeners is that speed and convenience are accomplished through an aggressive approach. The orbiting abrasive plates in the machine can remove significantly more material from the knife blade than if you were to use a sharpening stone. Regular use of an electric knife sharpener will shorten the lifespan of your knife.

German-style knives feature bolsters that will prevent you from being able to pull the knife all the way through. Using an electric knife sharpener — or a manual knife sharpener — means that you’ll be unable to sharpen the portion of the blade closest to the handle.

Japanese-style knives typically have no bolster, so this obstacle is removed. You’ll have another concern, though. Many Japanese-style knives feature a blade angle that’s more acute than German-style knives. Electric knife sharpeners are all about convenience, so the internal sharpening disks are positioned to match specific angles. You wouldn’t want to run your Japanese-style knife through an electric knife sharpener that was configured for German-style knives — or vice versa.

Manual Knife Sharpeners

These are also known as pull-through sharpeners. Take an electric knife sharpener and remove its motorized components. What you’re left with is a smaller, more portable version of an electric knife sharpener that also doesn’t need to be plugged in.

Otherwise, manual knife sharpeners work the same as their electrified cousins. The biggest difference is that your action of pulling the knife blade through the slots is what causes the orbiting plates of abrasive material to restore sharpness.

This manual action means you’ll likely have to pull the knife several times through each slot. If you have little or no experience in what to look for, it may be difficult to know how many times to perform this action. Keep in mind that like an electric knife sharpener, the first slot will feature an aggressive level of abrasiveness. It’s easy to inadvertently remove more of your knife blade’s material than what’s needed to re-sharpen it.

Manual sharpeners are smaller and easier to store, but you’ll also run into the same obstacles that you get with electric knife sharpeners when it comes to German-style knife blade bolsters and pre-set angles.

Sharpening Systems

The most difficult part of sharpening a knife is making sure you have the right blade angle. It’s why people shy away from maintaining their knives with sharpening stones. Sharpening machines remove this concern. A knife sharpening system holds the blade at the correct angle. Instead of pulling the blade across a series of sharpening surfaces, the knife is fixed, and the stone is moved over the blade.

It’s an option to consider, but the preparation may add more time than you’re willing to spend.

Sharpening Stones

Knife sharpening stone: a knife and ingredients on a cutting boardSharpening stones offer superior results for nearly every kind of knife.

This method of knife sharpening has a learning curve, and it takes more time than pulling your knives through a sharpening machine, but the results are superior. Sharpening stones can be used for German-style and Japanese-style knives. This method can sharpen nearly every kind of knife.

Unlike an electric or manual knife sharpening machine, you have to hold the blade at the correct sharpening angle. The result, though, is a freshly sharpened edge.

Sharpening stones are also known as whetstones. The word “whet” means to sharpen. A delicious aroma can whet your appetite, and a sharpening stone can whet your kitchen knives. The actual process of using a whetstone is known as stoning. The most common shape is a rectangular block, which is why they are also sometimes called a bench stone.

Nearly all sharpening stones require either water or oil as a lubricant to help reduce the friction of moving the angled knife blade across the surface of the stone. Choose sharpening stones that work best with water — and are therefore likely to be described as water stones – because they’re easier to work with. Oil stones are simply sharpening stones that work best with oil, which makes for a long clean-up.

What to Look for in a Sharpening Stone

Grinding tools against stone to sharpen the edges has been going on since — you guessed it — the Stone Age. Today’s sharpening stones are small in size because we are using them to sharpen a chef’s knife rather than a spear.

Sharpening stones can be cut from natural sources or created using industrial chemistry. The most common natural stone is crystalline silica, which is durable and extremely hard. Its abrasive qualities make it perfect for use in sharpening steel.

Man-made sharpening stones have become more popular, though, because it’s possible to create consistent particle sizes. These particle sizes determine the stone’s level of abrasiveness, which is also known as grit.

When using sharpening stones, you’ll start with a high level of abrasiveness and work your way towards a less abrasive surface that’s doing more polishing than grinding. Like sandpaper, lower grit levels indicate a higher degree of abrasiveness. 

Grit

Knife sharpening stone: sushi and a chef's knife displayed with ingredientsA quality set of sharpening stones will help you return a knife blade to razor sharpness.

The most common coarse sharpening stone is 220 grit. It’ll remove a large amount of blade material quickly, so it’s often used to grind away a chip or to even set a new bevel angle on a blade. The Japanese call this type of coarse sharpening stone “Arato.”

A medium grit stone is commonly around 1,000 grit. The Japanese call it “Nakato.” If your knife is dull but not damaged, you can start with this sharpening stone. The level of abrasiveness removes enough material to restore the cutting edge. It’s much less aggressive, so you don’t have to worry about inadvertently removing more material than necessary.

A very fine grit stone — which the Japanese call “Shiageto” — is 6,000 grit or higher. It’s used as the final step to polish and hone the cutting edge.

If you plan to maintain the sharpness of your blades using sharpening stones, you’ll need a minimum of three. A coarse stone for repair, a medium stone for sharpening, and a very fine one to hone. Misen offers a sharpening stone set made of premium materials hand crafted by Naniwa in Osaka, Japan.

Worth Your Time and Attention

Running your knives through a sharpening machine is quick and easy, and then you’re done – but is that all there is to cooking?

Many people want a deeper connection with what they prepare in the kitchen. Using sharpening stones takes longer than using a sharpening machine, and there’s more skill involved, but you’re rewarded with the satisfaction that comes when you choose what’s better over what’s easier.