How to Sharpen Cooking Knives

  • Have you ever tried to hang a picture frame or mount a TV using an ordinary screwdriver? The job probably would’ve been a lot easier with an electric drill, right? That same principle applies to the difference between a dull knife and a sharp knife — you want the tool that’ll make your work easier, which is why having a sharpened blade is so important. Rather than sawing at food and potentially cutting yourself with the slip of a dull knife, keeping your blades properly sharpened is essential for simpler and more enjoyable cooking.

    Before you grab your knives for a quick tune-up, it’s important to know that sharpening is actually a 2-step process: honing then sharpening. Honing is for general maintenance and aligning or straightening the knife, while sharpening is done to shave a dull blade into a razor’s edge. There are instances where an out-of-alignment knife simply needs to be honed, but you should always hone a blade before sharpening it.

While both honing and sharpening are fairly straightforward, we recommend you move slowly and cautiously when first trying these techniques (Mom told you not to play with knives, after all). It may take 5–10 minutes to fully sharpen your knives at first, but you’ll eventually become comfortable with the motions and be able to get them from dull to chef-sharp in no time!

How to Hone a Kitchen Knife

Knife edges are made of microscopic teeth that get bent out of alignment with ordinary use. This generally occurs before a blade begins to dull, so you’ll typically find yourself honing more often than sharpening. All you need to keep the edge straight is a honing steel, which is just a slender metal rod lined with grooves that realign blades drawn across its surface. Despite being called a “steel,” these tools can also be made of diamond or ceramic, but what’s most important is that the rod is at least as hard (but preferably harder) than your knife.

There are a few different options for positioning your honing steel, but the fastest (and most chef-like) method is firmly gripping the handle of the steel in your non-dominant hand with the tip facing away from your body. You’ll be drawing the knife toward yourself, so be sure to extend your arm a bit. Once you’re in a comfortable position, perform the following steps to hone your knife:

  1. Place the heel of your blade against the tip of the steel, tilting the edge so there’s a 20-degree angle between them (for those using Japanese-style knives, the angle should be closer to 10 degrees). If you’re using a steel from the same manufacturer as your knife, simply align the heel with the taper at the tip of the steel because it’s designed to guide you along the appropriate angle.

  2. Applying a slight amount of pressure, draw the knife down the steel at the necessary angle while also moving it completely across as if you’re trying to shave off slivers of the steel. This technique results in a sweeping or arcing motion that straightens the entire edge when done correctly.

  3. Repeat this motion from heel to tip about 8–10 times, gradually decreasing pressure with each stroke until you’re just gliding the knife down the steel.

  4. Perform the same technique for the other side of the blade.

Once you have the technique down, you may be able to alternate from side to side in a single motion.

Whether you go back and forth or fully tackle one side at a time, be sure to make an equal number of passes on both sides of the knife.

Though this method is the most efficient way to hone kitchen knives, we understand that it may be a little intimidating at first. You might be more comfortable with the alternative technique, which is done by firmly holding the steel tip-down on a cutting board directly in front of you. This makes both the steel and the knife slightly easier to control, though you’ll have to do some guesswork with the knife angle because honing in this position starts with the heel of the blade just below the handle. The actual honing method, however, is the same sweeping motion as described above.

How to Sharpen a Kitchen Knife

What if your properly aligned knife still doesn’t cut it in the kitchen? That’s one of the telltale signs that it’s time for a good sharpening, which is typically done with whetstones of varying grits.

Your sharpening stones can either be dry or wet with a small amount of water of oil. If you choose to moisten your whetstones, be sure to always stick with either oil or water because the substances don’t mix. Always place a damp towel beneath the stone to create surface tension that’ll prevent it from moving around your countertop while you grind the blade. Then it’s time to get to sharpening:

  1. Start with the coarse whetstone, again placing your knife at a 20-degree angle to its surface (remember, Japanese-style knives should be angled close to 10 degrees).

  2. With your dominant hand firmly gripping the handle and the fingers of your other hand applying slight pressure on the flat of the blade, grind the knife’s edge across the stone in an arcing motion similar to honing.

  3. Repeat the process on the other side of the blade, again aiming for 8–10 passes per side.

  4. Wipe the blade to clear away the grit and metal flakes that remain on its edge.

  5. Repeat the first 3 steps on a whetstone that has a finer grit, which is more for polishing the blade after you’ve created a sharper edge.

You can keep multiple single-sided sharpening stones or try to get your hands on a double- or even tripled-sided whetstone to avoid clutter in the kitchen. The Henckels 6-piece knife sharpening set is another good way to get everything you need in one neatly condensed package.

There are a few other sharpening options besides whetstones, most notably 2-stage honing tools. By grinding the blade across ceramic wheels set at the proper angles for both honing and sharpening, you have no guesswork whatsoever. If you have Western and Japanese knives in your kitchen, the Wusthof 4-stage knife sharpener is a great tool to have because it has wheels set to angles for both types of blades. Diamond honing steels, despite their intended use, can also be hard enough to grind away dull edges.

Finally, there's a huge selection of electric knife sharpeners out there that greatly simplify the whole process. These slotted sharpeners generally have 2 or 3 stages for overall knife maintenance along with settings that sharpen your blade just long enough for a flawless edge. While they save plenty of time, electric sharpeners aren't as immersive as their manual counterparts.

No matter how you decide to sharpen, doing so will enable your knife to take down even the toughest kitchen task. But if you want your blade to look as good as it cuts, you can further polish it using a leather strop. All you have to do is hang the piece of leather by one of its ends, hold the other end taut, and drag the edge of the blade down the strop with the edge facing upward.

How Do I Know if My Kitchen Knife Needs Sharpening?

After you’ve gotten used to your knives, you should able to tell if the edge is dull by feel when cutting. But for those who are new to blades or simply prefer a more exact science, there are a few common tests that reveal just how sharp your blade is.

A properly sharpened knife will easily slide through almost any food item you’re trying to cut — if you find yourself sawing, then your blade isn’t as sharp as it should be. Most people use a ripe tomato as the subject of the slice-versus-saw test, while others like to see if their knife can seamlessly slide through a piece of paper held in the air. We just can’t remember the last time we used diced paper in one of our recipes.

These tests are helpful because the frequency of honing and/or sharpening is dependent on how much use you get out of your kitchen knives. Do you regularly mince whole clothes of garlic and bags of onions, or do you only occasionally dice potatoes as a side for your steak? The more you use your knives, the faster they’ll come out of alignment and eventually dull.

That being said, many chefs hone and sharpen their knives before every use. It’s not a bad practice for home cooks, but it will add a few minutes to prep time. You can probably get away with honing before every big cook and sharpening a few times a year, but remember that the need for this type of maintenance will vary from cook to cook and knife to knife.