How to Tell If a Knife Is Sharp

We've all seen those mesmerizing informercials where someone slices through vegetables and random household items with ease.

But how is it done? With a sharp knife, of course!

There's something oddly satisfying about a sharp blade that makes cutting, slicing, dicing, and cooking safe and easy.

Not only is a dull knife frustrating to use but it can also be dangerous.

Here we'll cover how to tell if a knife is sharp and how to keep it that way!

Grab your cutting board and let's get into it.

How to Tell If a Knife is Sharp: 2 Simple Tricks

Before you take your knife to the prep table, how can you tell if it's sharp? There are a few tests you can perform to make sure your knife is sharp and ready for use.

1. Slice a Piece of Paper or Magazine

While this may not be the safest approach, you can test the sharpness of a knife using a single piece of paper or a rolled-up magazine.

If you're using paper, hold the sheet in front of you at arm's length with the wide edge facing your body. Hold one top corner firmly in one hand and swiftly run the blade from the top of the paper down with the other.

The blade should easily slice through the thin sheet without resistance. If it doesn't, it means your knife is due for maintenance.

If you really want to test the sharpness of your blade, you can try a similar method using a rolled-up magazine. Roll the magazine tightly and lay it on a safe cutting surface.

Hold one end of the roll with one hand and use your other to cut through the paper, as you would a loaf of bread.

The knife should make straight, clean slices through the paper. If it tears or rips, it means your knife is dull.

Following this experiment, be sure to properly clean the knife before using it on food.

2. Slice an Onion or Tomato

This is the more favorable and practical way to tell if a knife is sharp. After all, you're likely using your knives in the kitchen where food items like tomatoes and onions are readily available.

Place the onion or tomato on a cutting board and start slicing. Use long, steady strokes. The knife should slice through the food smoothly and with little pressure.

If you need to struggle or apply excess pressure to make the cuts, you have a dull knife on your hands.

The Truth About Dull Knives

There's no denying that a sharp knife in the wrong hands can be extremely dangerous. But did you know that a dull knife is actually more dangerous than even the sharpest blade?

Dull knives lead to complacent cooks. This is the number one reason to fear a dull knife. Remember, every knife is dangerous and should be treated that way.

It takes a lot more pressure and effort to cut using a dull knife. The more pressure and force you use, the more likely the knife will slip and cut you.

Not only that, but wounds from dull knives actually take longer to heal. Dull knives rip and tear items rather than slice them. If you cut yourself using a dull knife, it will leave a jagged, uneven cut that could result in permanent damage.

How to Properly Sharpen a Knife

Now that you know how to tell if a knife is sharp and the dangers of working with dull knives, let's discuss how to properly sharpen your tools. 

Honing vs. Sharpening

Almost every cutlery set comes with a long steel rod that people use to sharpen their knives. The truth is, this rod is actually used for honing and doesn't really sharpen the blade.

Instead, this rod straightens the cutting edge, evening out the surface and making for a smoother cut.

Sharpening, on the other hand, actually sharpens the blade itself. It's recommended you both hone and sharpen your knives for the best result. 

Knife Sharpening 101

When it's time to sharpen your knives, you can choose from two popular methods – using a whetstone or a traditional knife sharpening machine.

A whetstone is a popular, affordable option that is exactly what it sounds like – a rectangular stone that you soak in water before each use.

A whetstone works like sandpaper. As you slide the knife blade across the surface, it helps sharpen and refine the edge. 

Carefully hold the knife on an angle against the whetstone and gently drag each side across the surface a few times. Most stones have two sides – a coarse-grind side and a fine-grind side. 

The coarse-grind side is meant for duller knives but should be finished on the fine-grind side.

Some people prefer knife sharpening machines as a quick and fast solution. You simply press the blade into the coarse side first, followed by the fine side. Pull the knife toward you a few times before switching.

Most professional chefs prefer whetstones as some sharpeners can be rough on the knife edge. Switch between these two methods or reserve your best knives for whetstone sharpening only. 


How to Keep Your Knives Sharp

Now that you've gone through all that trouble to sharpen your knives you probably want to keep them that way!

Here are a few tips for keeping your knives sharper, longer.

How to Properly Sharpen a Knife

Now that you've gone through all that trouble to sharpen your knives you probably want to keep them that way!

Here are a few tips for keeping your knives sharper, longer.

Create a Maintenance Schedule

Just like any other tools, your kitchen knives need regular maintenance – including sharpening and honing.

Create a schedule based on how often you use them. You should hone your knives after every few uses. If you're diligent with this, you should only have to sharpen your knives once or twice a year.

Wash Them By Hand

It can be tempting to toss your knives into the dishwasher with the rest of your utensils, but don't! Quality knives need proper care and that includes washing them by hand.

The heat and detergent from your dishwasher can dull your knives quickly and may even cause damage. 

Store Them Properly

Storage is another important factor when it comes to keeping your knives sharp. 

Don't throw your knives into the same drawer as the rest of your utensils. This can lead to accidents and dullness.

Designate a specific spot for your knives. Popular choices include a magnetic board for easy access or a counter top knife block. 

Sharp Ideas for Sharp Knives

Whether you're a chef or just enjoy cooking, knives are an essential kitchen tool. Knowing how to tell if a knife is sharp and how to perform proper maintenance guarantees your knives withstand the test of time.

Ready to invest in a quality set of steak knives? Browse our selection today!