The simple trick for sharpening a knife with a coffee mug

There are a lot of mistakes everyone makes with kitchen knives, from using the wrong knife for the job to putting them in the dishwasher when they really should be washed by hand. But one of the worst things you can do with your knives is to sharpen them with an electric sharpener (via Serious Eats), which is why we're so in love with this simple trick for sharpening a knife with a coffee mug.

Using a sharpening stone is the best method for giving your knives a good edge, but there's a steep learning curve, and the stones can be fairly pricey. That's why the mug trick is so handy – it can help you sharpen your knife using something you already have on hand, but won't actually damage the knife blade.

How to sharpen a knife with a coffee mug

Whether you're at home and don't have any way to sharpen your knives, or if you're on vacation and the knives in your rental are dangerously dull, the coffee mug sharpening trick can come in super handy.

You can't sharpen your knives on the shiny, glazed part of your mug. What you want to do is turn the mug over, where you'll see an unglazed ceramic rim (via Serious Eats).

To sharpen your knife blade, you need to glide the knife blade along the unglazed ceramic edge, at an angle of 15 to 20 degrees. You should start with about 10 strokes on each side, slowly reducing the number of strokes until you have a nice edge on the blade.

The reason why this method works is that unglazed ceramic is actually harder than metal. You can also use the unglazed ceramic edge you find at the bottom of plates and bowls to sharpen your knives, or even the top edge of a rolled down car window (who knew!).

Sharpening your knives on unglazed ceramic like this may leave a mark on your mug, plate, or bowl, but it can be washed away. You also shouldn't use this as your default method of knife sharpening, but more as one you turn to in a pinch, because this method removes a lot of material from the knife's edge and can shrink the blade over time.