Life Skills: How to Sharpen a Knife

Of all the tools in your kitchen, your knives deserve the most care and respect.

There is no greater hindrance to the home cook than a stash of dull knives. Even if it’s a durable Wusthof, Victorinox, or Shun Classic, your knife is only as good as the sharpening job on its blade. The only kitchens I’ve been in where there are sharp knives include restaurants (who sharpen their knives religiously), the fancy ones that have seen maybe two meals in their existence, and, of course, my parents’. In our second of three videos with ‘Knife Master’ Eytan Zias and food expert Josh Ozersky, we learn how to sharpen a knife.

A dull knife can actually be more dangerous than a sharp knife; if your knife doesn’t slice through like butter, you might feel inclined to apply more pressure and that can compromise control and damage the food, or worse, you. Delicate ingredients like fresh herbs and tomatoes will wilt when sliced with a dull knife because it crushes more of the cells surrounding the cut. More importantly, a dull knife slows you down in the kitchen, while a sharp knife makes cooking easier and more enjoyable.

You may be asking yourself, “Do I care enough about cooking to actively keep my knives sharp?” And the answer may be no, or you may realize that sharpening your knives is less wasteful and more cost-effective than buying new ones. And who knows, maybe you’ll find out that sharp knives were the missing piece between you and kitchen glory.

Sharpening Process

If you want your blade to split atoms, there is no doubt that you’ll need to get a whetstone. Sharpening stones come in a wide variety of grains or roughnesses to tailor your edges to your personal cutting style (polished vs. toothy, precision vs. durability, etc.). The higher the number, the finer the grit. Here are a few sharpening tips from Eytan Zias of Portland Knife House.

1. Use waterstones over oil or diamond stones — Waterstones are efficient, cost effective, and leave the best edges. The only stones you really need are a medium grit whetstone and a flattener (both start at about $25). Avoid anything with set angles or mechanical sharpeners — free hand sharpening is the only way to go. The best way to find your edge angle is visually, and using a Sharpie will help with that (hence, why they call it a Sharpie…).

2. Sharpening is about grit and angles — As long as you control these it doesn’t matter which sharpening technique you use. Zias sharpens back and forth, or Japanese style, since he finds it to be the most effective way for getting a clean burr, or wire edge, result. And because the knife never leaves the stone and the fingers never leave the knife, it reduces angle variation to make sure your blade is sharpened evenly.

3. Burr (Wire Edge) Formation — Burring is arguably the most important aspect in knife sharpening. The wire edge of the blade is the result of the angle in which the knife was sharpened. Zias sharpens one side at a time, with guidance from his sharpie marks, until there’s a small edge of overhanging steel.


When de-burring, or when the sharpening shenanigans conclude, use very light pressure and alternate your strokes on each side. The goal of de-burring is to loosen or remove the wire edge on your blade without creating a new one. When finished, the blade should feel smooth on either side, but “bite” when felt straight on.

Zias finishes all his edges on a leather bench strop with diamond abrasive spray.

One of the biggest keys to keep your knife spiffy and sharp is maintenance–and you can do that with a honing rod; you know, the steel, wand-shaped device on your knife block. While honing rods are great for maintaining the edge on your knife, they’re not particularly useful when it comes to actually sharpening your blade. “If you use stones, I generally tell people that they don’t have to use steels,” says Zias. However, he admits that using a honing rod is better than nothing.

Using a whetstone is the manliest and most cost-effective way to keep your blades deadly and true. Once you know how to sharpen a knife properly, you’ll find that vegetables tremble in your presence.

Editor’s note: While Josh Ozersky unfortunately died in May of 2015, we want continue to honor and promote him and the amazing work he did for us and food culture in America. Rest in Peace, Josh.

Article originally published April 10, 2015. Updated November 4, 2016 by Bryan Holt.