Aluminum foil trick: How to sharpen your dull kitchen knife in 7 steps

A dull knife can make chopping vegetables, fruits and meat more difficult—and even increase the risk of slipping. While aluminum foil isn't a replacement for a professional knife sharpener, it can help refine the edge of a slightly dull blade. Here's how to try this easy kitchen hack at home.

You'll need:

• Aluminum foil
• A cutting board
• Your kitchen knife
• A clean cloth

Fold the aluminum foil into a thick strip by folding it over several times.

Hold the folded foil firmly on a cutting board and make several long slicing cuts through it using the knife. Repeat the motion 15–20 times, alternating sides of the blade for even contact.

After cutting through the foil, wipe the knife with a clean, damp cloth and dry it thoroughly. This removes any tiny metal particles or foil residue left on the blade.

Try slicing a tomato, onion or a sheet of paper. If the knife feels slightly smoother, the foil may have helped refine the edge. If it's still very dull, it likely needs proper sharpening.

Aluminum foil is not a substitute for a whetstone or knife sharpener. It works best for blades that have only lost a little sharpness and may help remove tiny burrs rather than restore a heavily worn edge.

To keep your knife sharper for longer:

• Use wooden or plastic cutting boards.
• Avoid cutting on glass, ceramic or stone surfaces.
• Hand-wash knives instead of putting them in the dishwasher.
• Store them safely in a knife block, magnetic strip or blade guard.