The Real People's Guide to Sharpening a Knife

A man sharpening a knife in the kitchen
Lew Robertson / Getty Images

They say you continue to evolve as long as you live.

I can't speak for everyone, but I certainly feel like I've evolved since the first time I wrote about knife sharpening, way back in 2008, shortly after the dawn of time.

In those days I was young and idealistic, full of vinegar and that other thing. I dreamed of a utopian society where everyone owned a whetstone and a sharpening steel, where knives never went dull, where even the toughest tomato skin would yield to the feather-light touch of finely honed carbon steel, and where no one — not even the clumsiest among us — would ever cut themselves again.

A little bird even landed on my typewriter when I wrote it, so I knew it had to be true. (That's right, we used typewriters in 2008. When I finished an article I'd seal it in a canister and shoot it into a pneumatic tube that was linked up to the Inter-Nets.)

That's how it was in those halcyon days. And I wouldn't have it any other way. What, after all, is youth FOR if not for dreaming big dreams?

But not all dreams work out. As you careen through the years, you learn to accept this fact. Not every kitchen has a magnetic strip for holding knives, for example. And you're never going to install one, either, no matter how many kitchen remodel shows you watch.

No, you'll store your knives loose in a kitchen drawer, where they'll be knocked around brutally by your other utensils, savaging their flawless, factory-honed edges. And yet, behold! The earth will not open up and swallow you whole, despite the admonishments of Ye Olde Internet Writers.

Next, still reeling from this lesson, perhaps you'll have children, and now you won't even USE knives anymore. Your entire dietary intake will now consist of leftover hot dogs and chicken nuggets that your child demanded and then refused to eat because "they're too round."

Worse still, even if you do manage to make yourself a proper dinner (once a year or so), you'll perceive yourself, as if from a great distance, tossing your $600 Shun Hana chef's knife into the dishwasher, and through the fog and cobwebs of what remains of your mind, you'll dimly realize that you're just too tired to care.

Finally, there's divorce, and as you're unpacking your things at your new place, you'll discover, with a touch of nostalgia, that you don't even have that knife anymore. And so you'll trek down to the supermarket where, along with your new dish drainer and mop and cleaning supplies, you'll pick up a $12 kitchen knife.

And that's the moment your new life really begins.

Sharpen Your Mind, Not Just Your Knives

To be clear, your new life does not involve letting yourself go. This isn't about giving up — on yourself OR your knives. 

Rather, it's about gaining clarity.

Thus, while you will remain ever mindful of the importance of keeping your knives sharp (no less so for your $12 supermarket knife than for your long-departed Shun), no longer will you indulge whimsical fantasies of becoming an itinerant knife sharpener, plying your trade at neighborhood street fairs alongside vendors of artisanal pickles and small-batch dog food.

No, from now on you'll purchase tools that are appropriate for your needs and your means, and if that means buying a cheap knife, so be it. Cheap or not, one thing that's not optional is keeping it sharp.

For one thing, it's easier to work with a sharp knife, because a sharp knife does its job with less pressure from you.

And because you don't have to press down as hard, you're less likely to slip and cut yourself. Likewise, less pressure means that if you do cut yourself, it's more likely to be a minor nick than something much worse.

Speaking of knives, when you're ready to step up from the $12 knife, this 10-inch chef's knife by Victorinox will run you less than $40 and it's an excellent knife for the money. No hurry, though.

Before we go any further, let's talk about what sharpening is and isn't.

Sharpening a Knife Grinds Away Steel

The cutting edge of a typical kitchen knife is shaped like a V. If you looked at a brand-new knife with a factory edge under magnification, that's what you'd see. Different knives have different angles, and some of them even have what are called double-beveled edges, where you have a primary edge face which is ground to, say, 20 degrees, and a bevel, at the very edge of the edge, if you will, that's, say 15 degrees or sharper.

Remember, all this is visible only under magnification. 

The smaller the angle, the sharper the blade, and the more difficult it is to maintain that edge. 

After using it for a while, or letting it bang around in your drawer, that V turns into a U. And you won't need magnification to know it; it'll be obvious by how poorly the knife cuts. You'll have come to a moment of reckoning. Or actually, sharpening.

Sharpening a knife requires grinding away a certain amount of steel while maintaining that 20-degree angle. There's no way to turn a U into a V without grinding away some of your knife.

To do that, you have three choices:

  1. Do it yourself with a whetstone
  2. Do it yourself with a manual or electric knife sharpener
  3. Take it to a professional knife-sharpener
     

You may have noticed that I didn't mention anything about using a knife steel, which is sometimes misleadingly called a sharpening steel. And the reason for that is, a knife steel doesn't sharpen (i.e. grind away any steel), it merely hones the edge once it has been sharpened.

Sharpening? Honing? What in the world is the difference? Don't worry about it yet. We'll get to it shortly.

How to Sharpen a Knife Yourself

In my more militant days, I would swear that manual (i.e. "pull-through") or electric sharpeners were to be avoided at all costs. "They're bad for your knives," I complained. "They grind away too much steel."

Yes, that may be true. And if you use one to sharpen a $600 knife, you will lose your cutlery privileges for a period of not less than one year, and be forced to perform scut work in my kitchen. If you're talking about a $12 knife, on the other hand, "who cares?" is, in fact, a reasonable attitude.

You can usually find used sharpeners at thrift stores and yard sales, and especially in your parents' cupboards. If you want to pick up a new one, the Chef's Choice 450 is a decent manual sharpener, as is the Chef's Choice 110 in the electric category.

If you're using one of these types of sharpeners, follow the manufacturer's instructions, and most importantly, don't blame me.

Let's move on to whetstones. The nice thing about whetstones is that, unlike so many other kitchen gadgets, a whetstone will never stop working. Indeed, a whetstone is nothing but a flat piece of stone, and it will go on being a flat piece of stone for a very long time. As with the other types of sharpeners, if you're going to experiment with a whetstone, it's only sensible to start off with a knife you don't particularly care about. 

Get yourself a two-sided whetstone, with a coarse grit on one side and a fine grit on the other. Start off with the coarse side, giving the knife ten strokes on each side of the blade, keeping it at a 20-or-so degree angle. Then flip the stone over and give the knife the same treatment on the fine-grit side.

By the way, people sometimes hear the word whetstone and get the idea that it's referring to a wet stone. Which is an easy mistake to make, and the fact that there's a type of sharpening stone called a waterstone only adds to the confusion. 

But waterstones are a different beast. They need to be soaked before using and require a steady stream of water to be dribbled onto them during sharpening. Ordinary whetstones work best dry. In fact, the tiny particles of steel that the stone grinds off can become suspended in the liquid and actually damage the blade. This is true of water and especially oil, which is another substance people often misguidedly apply to their whetstones, presumably with the goal of lubricating it. 

Here's more about sharpening a knife with a whetstone.

Honing a Knife with a Honing Steel

Finally, once you've refreshed the edge on your knife, you need to hone the edge to make it true. What happens when you grind a new edge onto your knife is that the extreme edge of the blade becomes microscopically thin. That is why it's sharp. But being so thin means that it is easily bent to one side or the other, causing the knife to seem dull. It isn't dull, it's what's called out of true.

The remedy to this is to hone the edge of the blade on a steel. Unlike sharpening, honing doesn't remove any steel. Rather, it straightens out that curled edge.

Note that in addition to honing the knife after sharpening, it's a good idea to give you knife a few strokes on a honing steel anytime you start working with it. If you're slicing or chopping for an extended period of time, your knife may benefit from a few strokes on the steel every ten minutes or so.

A smooth steel is best, rather than the grooved kind. A ceramic steel like this one is an excellent choice. Diamond steels are also good, but some of them can be too abrasive.

To use a steel, hold it upright with the tip against your cutting board. A towel on the cutting board will help keep the tip of the steel from slipping. Slide your knife downward along the steel, using the same 20-ish degree angle as you did when sharpening, giving it ten strokes on the left side and ten on the right. 

By the way, forget about that criss-cross maneuver chefs do on TV. They're just showing off, and not only is that method no more effective, it's much more likely to result in a serious injury. 

Here's more about how to use a honing steel.

If all this talk of angles and double bevels is overwhelming, taking a knife to a cutlery store for sharpening a couple of times a year is perfectly acceptable and might ultimately be the best trade-off in terms of time and money. Just remember that even if you have someone else sharpen your knife, you'll still need to hone it from time to time.

The Secret to Storing Your Knives

And finally, here's a tip about storing your knives. Sure, those magnetic strips are fine, but I'd worry about a knife getting knocked off and stabbing someone in the foot, so I don't know. Knife blocks are fine, too, if you've got the counter space. But remember that your knives need to go in upside down, so their edges don't rest directly on the wood, which will knock them out of true. 

The best way to store a kitchen knife, actually, is in a drawer, but ONLY after first protecting it with an inexpensive knife guard, which you can buy individually or as a set. With these nifty accessories, your knives can rattle around inside your drawers without being damaged — and they also protect you from getting cut when you're rummaging around for something.