Culinary Arts

The Best Ways to Sharpen A Knife - Everything you Need to Know about Knife Sharpening and Benefits of a Sharp Kitchen Knife

Written by MasterClass

Apr 30, 2019 • 4 min read

If your kitchen knife is mashing instead of slicing your tomatoes or slips when cutting onions, it’s time to sharpen it. Whether you use a manual sharpener, an electric sharpener, or have the ability to use a whetstone, knife sharpening is a skill every home chef should learn.


The Benefits of a Sharp Knife

A sharp knife slices through your vegetables and cuts up your meat quickly and precisely. There are two main benefits to keeping sharp knives:

  1. Safety: A sharp knife is a safe knife. A dull knife is more likely to slip, cutting something else like a finger.
  2. Precision: A sharp knife makes precise cuts. The way you cut your food affects how long it takes to cook, so it’s important to cut food into even pieces enabling the food to cook at the same rate.

3 Ways to Test If a Knife Is Sharp:

  1. Paper test: A sharp knife should slice through a piece of paper easily.
  2. Tomato test: Tomatoes have a tough outer skin with a very soft interior, meaning that a dull knife will squish a tomato before breaking the skin.
  3. Onion test: Try cutting an onion’s outer skin. A dull knife will not be able to cut through it.

3 Ways to Sharpen Your Knife Yourself

Sharpening a knife is the process of removing metal from the blade of a knife to form a new sharp edge. There are three ways to sharpen a knife yourself:

  1. Manual knife sharpener. A manual knife sharpener, also called a “pull through sharpener,” is the cheapest and easiest way to maintain your kitchen knives. A manual knife sharpener has two slots: a course grit, to sharpen, and a fine grit, to polish.
  2. Electric knife sharpener. An electric knife sharpener is similar to a manual knife sharpener, with the same “course” and “fine” slots, but the abrasives are on motorized wheels that spin against the blade. Electric knife sharpeners are much more powerful and precise than manual knife sharpeners.
  3. Whetstone. A whetstone is a rectangular block with a coarse grit side and a fine grit side. A whetstone, or sharpening stone, is the most precise way to sharpen a knife.

How to Use a Manual Knife Sharpener

  1. Pull the knife through the course slot of the sharpener, from the heel to the tip, using even pressure, three to six times (pull through more times for more dull or damaged knives).
  2. Finish with one or two pulls through the fine grit side.

How to Use an Electric Knife Sharpener

  1. Pull the knife through the slot slowly and smoothly, letting the motorized abrasives do the work.
  2. Alternate to the knife’s other side and repeat step one. Repeat these steps three to six times
  3. Repeat steps one and two in the fine grit slot.
  4. If still not sharpened to your satisfaction, repeat these steps until sharp.

How to Use a Whetstone

Before you begin to use a whetstone, figure out the correct sharpening angle for your knife. Most knives have a 20-degree sharpening angle, and some Japanese knives should be sharpened to a 15-degree angle. Check with your knife’s manufacturer if you aren’t sure.

Your whetstone may need to be lubricated with a small amount of mineral oil, or honing oil, before use.

  1. Submerge the whetstone in water until it’s completely saturated and no air bubbles remain (this takes five to 10 minutes).
  2. Place the whetstone, course side up, on the counter. Place the edge of the knife blade on the stone at the correct sharpening angle, with the blade facing away from you.
  3. Grip the handle with one hand and place the other hand on the flat side of the blade, applying slight pressure.
  4. Drag the heel of the knife down the whetstone towards you, keeping the blade at a constant angle, until the tip of the knife runs off the edge of the stone. Repeat this motion three to six times. This should feel like circular gliding motions. Watch for a burr to form, which is a bit of metal that folds over the edge of the blade as you sharpen.
  5. Once the burr is formed along the entire edge of the knife, repeat steps three and four on the opposite side.
  6. Flip the whetstone over and repeat steps three through five on the fine grit side.

How do you Sharpen a Serrated Knife?

Serrated knives, like steak knives or bread knives, can be sharpened using a manual or electric knife sharpener. To sharpen a serrated knife, use only the “fine” slot, where the abrasive material conforms to the shape of the serrated knife.

What Is a Honing Rod and Will it Sharpen Knives?

Honing rods, sometimes called a sharpening steel or a honing steel, are long metal rods, often included in knife sets. Honing rods are not a knife sharpener at all and are only meant to maintain the shape of a sharp blade.

How to Use a Honing Rod

  1. Stand the honing rod up on a counter or table, perpendicular to it, and position the knife edge at a 15 degree angle to the rod.
  2. Sweep the blade along the steel, switching sides, until it realigns the edge.

5 Safety Precautions to Keep in Mind When Sharpening Knives

Sharpening knives poses similar dangers to your fingers as when using knives to slice your food, so keep these precautions in mind:

  1. Never expose your fingers to the blade.
  2. Wear kitchen gloves for extra precaution.
  3. If using a whetstone, make sure you are holding the stone in place or that it’s affixed to the table with a rubber mat or with damp paper towels placed, folded under the whetstone.
  4. If using a honing rod, hold the honing rod and the knife out and away from your body.
  5. After sharpening, remove any lingering steel shavings by using a wet sponge or dish towel.

How Often Should I Sharpen my Knives?

Sharpen your knives every six to 12 months to maintain a properly sharp knife. In between sharpenings, use the honing rod or run your knife through the “fine” setting of a sharpener after each use.