How to Sharpen a Knife

Keep your knives on the cutting edge with regular honing and sharpening.

Randi is a freelance writer for MarthaStewart.com.

What's the sharpest tool in your drawer? If your answer doesn't include one of the several knives you depend on to make quick work of chopping, dicing, carving, or other routine cooking tasks, then it's time for a honing or sharpening session (no, they're not the same thing!). After all, a dull knife can put a dent in your cooking routine—and do more harm than good. Here's what you need to know about sharpening and honing tools, and how sharp knives can, well, sharpen your kitchen skills.

"With a sharp knife, you can work faster, more precisely, and safely," says Ronna Welsh, chef and owner of Purple Kale Kitchenworks, an online cooking school, and author of The Nimble Cook. Sharp knives are substantially safer than dull knives, confirms Bobby Griggs, vice president of Hammer Stahl Cutlery. "Dull knives often lead to mistakes due to exerting more effort into the cutting process," he says.

In addition to being safer, sharp tools also help you up your culinary game, whether you're butterflying chicken breasts or assembling a mirepoix for a stew. "Keeping the knife sharp will improve your precision when cutting, and food that is cut even, cooks even," says Griggs. Sharp knives, in other words, yield better results.

How often you sharpen your knives may depend on the materials they're made of. Welsh says that a ceramic blade holds its edge longer than stainless steel, while carbon steel is easier to sharpen. "My general rule of thumb is to sharpen the second your knife sounds like it's crunching through the food. When it's really sharp, the knife should glide right through, no matter how dense or tough the ingredient," she says.

Hear us out: The easiest way to sharpen your knives is to keep your knives sharp. Enter the maintenance method called honing (this is different than sharpening), which makes use of a honing steel, also known as a honing rod. Using one ensures your knives are razor-sharp, each time you pick them up. "The point is to consistently hone your knife with a quality honing steel to keep the blade aligned," explains Griggs.

Honing involves holding the honing steel and knife at the angles suggested by the manufacturer and pulling the knife along the rod toward the tip—then repeating and alternating the process on both sides of the knife blade. "After a few strokes, check the sharpness of the blade by gently slicing a piece of paper," says Griggs. "If the knife cuts through the paper easily, it's adequately honed. If not, repeat the honing process until the desired sharpness is achieved."

Welsh reinforces the importance of honing during her classes. She advises starting with a good baseline edge and maintaining it with a honing steel. "Once you are comfortable sharpening with a steel, you'll be able to use a whetstone on occasion with no problem," she says.

While honing realigns the blade's edge, it won't remove any chips or nicks. Sharpening gets rid of material from the blade, creating a sharp new edge. "We always recommend primarily using a honing steel or device to help straighten and thus sharpen the blade without the removal of material from the knife itself. However, if the knife needs to be truly sharpened, there are some advantages and disadvantages to the different styles of sharpeners on the market," says Griggs.

Beyond honing rods, primary sharpening options include pull-through sharpeners, electric sharpeners, and whetstones. Welsh and Griggs, like most culinary professionals, prefer honing steels and whetstones. Hammer Stahl sells both tools together in its sharpening system. Whichever device you choose, knowing the correct angle to position your knife blade with the sharpener is critical to successful results.

Whetstones (or sharpening stones) are flat blocks of abrasive material made from aluminum oxide, ceramics, steel sheets coated with diamond particles, or natural stone. Some have two-sided granulations that allow for general manual sharpening and a finishing edge. They need to be soaked before use and kept wet while rubbing the blade against the stone.

So, why is a whetstone the better sharpening option? "Whetstone sharpeners give you more control over how your knife is sharpened," says Welsh. A multi-grit whetstone combined with either a honing rod or a good piece of leather to help burr and polish the edge is one of the best ways to manage your knives, adds Griggs. "The whetstone approach allows you to sharpen at a multitude of angles as well as most types of steel," he says.

Still, it may take practice, patience, and confidence to use a whetstone correctly—all of which can be gained with time.

How to Sharpen a Knife with a Whetstone

Always submerge a whetstone in water until there are no visible air bubbles before using. This can take 10 to 45 minutes, depending on the whetstone.

While a whetstone manually sharpens the blade, an electric knife sharpener uses powered abrasive wheels or discs to achieve that goal. There are pluses and minuses to electric sharpeners. "Good electric sharpeners can produce a good, sharp edge, but they often wear away at your knife's edge quicker over time," says Welsh.

Griggs points out that while an electric sharpener is typically faster and more convenient, quality units can be pricey and more aggressive, especially if you fail to accurately follow the guidelines. "Electric sharpeners oftentimes are more restrictive to blade angles, reducing its flexibility among your collection," he says. Many Damascus knife brands discourage the use of electric sharpeners, says Griggs.