How to Make Your Kitchen Knives Last Forever, According to a Professional Chef

With the right tools and techniques, home cooks can easily restore a dull knife to peak performance. nito/Shutterstock

If you’re like me, you probably have a collection of kitchen knives in various states of usefulness. You know—ones so dull they’ll smash a ripe tomato instead of slicing it. Compare this to a well sharpened blade: When drawn lightly across the surface, it glides through with the weight of the knife alone, no extra force needed.

At the other extreme, my grandfather so excessively sharpened a knife over the years that the edge of the blade took on a wavy shape half its original width.

Since a good knife doesn’t come cheap, it’s important to properly care for your investment. I asked chef Michael Handal, an instructor at the Institute of Culinary Education in New York City, how to take care of a kitchen knife.

Chef instructor Michael Handal. Courtesy of the Institute of Culinary Education

Cleaning and Storage

First, Handal gives an emphatic warning: “Please do not clean your knives in the dishwasher!” Detergents and salts used to eliminate streaking can cause corrosion and blunting, while high temperatures and extreme water pressure can even dull the blade or damage wooden handles.

Instead, carefully hand-wash the blades with soap and hot water.

“To avoid cuts, be sure to clean and wipe blades from the back of the blade, wiping toward the sharp edge of the blade—never in reverse,” Handal said.

Hand dry them immediately. Especially when the knife has a wooden handle, you don’t want the knife soaking for any period of time.

Be sure to store them safely, too. A loose knife in a drawer may surprise you when you go digging for something else. Handal recommends knife guards correctly sized to the particular knife. Alternatively, sets of blades often come with a protective knife block.

Staying Sharp

No matter how much money you’ve spent on a knife, every time you use it, it’s losing its effectiveness. That’s normal. There are two ways to restore it: honing and sharpening.

Honing

Honing a knife—keeping its edge straight—is just as important as sharpening. With repeated use, the microscopic metal fibers that make up the blade will bend, causing a warping you can’t see. Over time, it makes your cutting edge less effective.

“Honing is going to initially re-align an already sharpened knife edge,” said Handal.

Home cooks should hone a knife once or twice a week. This is accomplished with a steel or ceramic honing rod, sometimes referred to as a sharpening steel. Some knife sets come with one included. Handal recommends the Wusthof 10-inch Sharpening Steel ($50) as a good entry-level tool that is readily available.

“It has a good graining pattern that is suitable for most Western-made knives, such as Wusthof and Zwilling,” he said.

Draw the full blade along the rod at the angle recommended by the manufacturer, generally 15 degrees for a Japanese knife and 22 degrees for a Western-style knife. Don’t rush. Repeat this several times on either side of the blade, and don’t feel you need to apply great pressure; it’s a gentle process. The repeated friction along the edge of the blade straightens those errant fibers.

Honing a knife with a honing rod realigns the edge, which will imperceptibly bend with repeated use. Courtesy of the Institute of Culinary Education

Sharpening

When you notice your knife doesn’t easily glide through what you’re cutting, and honing no longer helps, it’s time to sharpen it.

Sharpening is a more intensive process. It involves using a sharpening stone or wheel to grind the thickened blade edge “to a precise angle,” Handal said, removing some of the steel. The angle depends on the knife and its purpose. For kitchen knives, aim for an angle of 17 degrees to 20 degrees to give good sharpness while maintaining the blade’s strength and durability. An exception is an Asian-style knife, such as a santoku, which needs an angle of 10 to 15 degrees.

Home cooks likely only need to do this once or twice a year. But don’t put it off.

“The biggest mistake that even professionals sometimes make is to wait too long to go to the sharpening stage, and rely on simple honing,” warned Handal. “This makes the sharpening step more time and labor intensive.”

Sharpening stones, also called whetstones, come in different grits, or degrees of coarseness—think of them like sandpaper. The grit number indicates the size of the abrasive particles. The higher the number, the smaller the particles, and thus the smoother the finish.

The higher the number, the smaller the particles, and thus the smoother the finish. Lower grit numbers remove more metal and are intended for more damaged blades. If your knife is very dull, you may need to start with something in the lower range of 200 to 500 grit, and finish with a higher grit between 2000 to 5000. Only in the case of a specialty knife with a razor-sharp blade will you need stones up to 10,000-12,000 grit, said Handal.

Pull-through sharpeners are an easier alternative, but be aware that they take off more metal and that may shorten the life of your knife, especially if you sharpen too often.

For the home cook, Handal recommends a combination whetstone with a 400-grit surface on one side and 1000-grit surface on the other. He likes the King brand of stones, which are Japanese-made and affordable.

“We used this setup at the Institute of Culinary Education for many years,” he said.

He also favors the Naniwa brand, also from Japan. You’d need to purchase a separate stone for each grit level. The advantage here is having more precision in the sharpening process as you become more familiar with the process.

Honing and sharpening may be a bit intimidating at first, especially if you’ve paid a lot for a knife. Handal recommends watching online instructional videos before you try, citing an abundance of material online, especially on YouTube or on your knife manufacturer’s website. Both Wusthof and Zwilling have very good information on the sharpening procedures for their knives, including the angle you should be using for each particular knife.

Well taken care of, a quality knife will last a lifetime.

Sharpening a knife on a whetstone removes some of the steel to grind it to a sharp point. stella_photo/Shutterstock