How to Tell If a Knife is Sharp or Dull – Testing Methods

Normally people think that if the knife can cut then it means it is a sharp knife but it is not true. No one can tell you a dull knife from a sharp knife. A dull knife will usually cut but it requires force and energy while cutting. On the other hand, the sharp knife can easily cut everything without any extra potency. So how can you tell if a knife is properly sharpened ? 

In the following section, we have defined some way to determine the sharpness of the blade. Let’s come to discuss them.

Fingernail Test 1

If the knife drives on your thumbnail, it’s dull and you need to put a new edge on it. If it is flat, it has at least a basic level of sharpness.

Fingernail Test 2

This test will tell you about damage other than sharpness. In which you need to run the edge of your fingernail with the complete length of the cutting edge to feel where the chips occur. If you are sharpening a chipped knife with coarse stone then stay on coarse stone until you did not feel any chip before moving to medium one.

Examination Under the Bright Light

Move your knife so that the cutting edge is facing up and then look closely under a bright light. Small bits tend to bend or chip during normal use. This lets you see them as bright and shiny spots.

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Paper Cutting

Cutting a paper with your knife is another method to tell you how sharp your knife is. The thicker the paper the easier it is to cut. If your knife is sharp enough then it can easily cut standard paper. The newspaper has a thinner paper and a highly sharp knife can cut it with some difficulty, if you cut the newspaper smoothly then it means your knife is sharp nicely. Furthermore, toilet paper and kitchen towels are hairy and extraordinarily hard to cut, for cutting these things you need to sharpen your knife to make smooth edges.

Push Cut Test

This involves cutting the paper by pushing it straight down without cutting it (forward or backward). But this test is not compatible as it depends upon how close your finger is while cutting the paper and what type of paper you are using. As it is a very difficult test and it requires a very sharp knife to pass this analysis. Remember that thinner paper is harder to cut.

Tomato Test

Tomato test is very popular but we did not recommend it. The sharp knife can easily cut the tomato easily but an old tomato will be difficult to cut with any knife and technically, the small serrations of a less sharp knife can help the tomato break the skin.

Shaving Test

This test will tell you, have you completed your sharpening or not. Pass the knife’s blade side on your arm at a shallow angle and touch the skin. If you see your skin’s hairs have been removed which means blade sharpening has been passed by your knife.

Hanging Hair Test

Hanging hair test also tells you about your knife sharpness. You just have put the knife upside down with the cutting side face up. Now hold the hair at a distance from blade and down it slowly slowly until it touches the blade and will be cut. This result will only be achieved through fine edges or strops. Your knife shows highly sharpness if it passes this test.

Why is a Sharp Knife Safer than a Dull Knife ?

Yes, sharp knives are safer than dull knives because they can cut the food more effectively with zero force. But when you use a dull knife, you need more pressure and force to get your job done. 

These things increase the chances of accidentally cutting yourself. Sharp knives have less friction between their blade and whatever you are using to cut and also low chances of slippage. It provides more precise cuts of your food. 

The optical attraction of food is as important as taste, smell and texture. The sharp knife provides you nice shape and size food which will be appreciable by your guest as well.

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To test the sharpness of your knife, you should cut something every day. Tomatoes and onions are a bit softer and offer stiff resistance when you run the blade across the surface though so this would be a great option to test the quality of the knives. Apples and carrots also work in juicing, but they have more of a biting motion. 

Additionally, you should sharpen your knife when you see it to prevent it from getting damaged. You can use a honing stone or a steel rod for sharpening. It cleans the knife edge instead of removing metal to create a new edge. 

Simply, you can say that knife maintenance is essential in the kitchen and you should treat your tools with respect so that you can use them anytime and prepare all kinds of incredible dishes that you want. Guests will want more!

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