How to sharpen a potato peeler without any tools

This “sharpening” trick utilises the fact that if your potato peeler has a symmetric blade. If you are only using one side of it, the other side stays sharp as new. So, to make the peeler sharp again, you simply need to start using the other side of the blade. No special sharpening tools are required: you simply need to turn the blade around:

Taking blade out of the peeler.
Quick peeler sharpening, step 1: bend the end of the blade-holding arch outwards so the blade falls out.
'Sharpening' the peeler blade by turning it around.
Quick peeler sharpening, step 2: turn the blade and place it back in by bending the blade-holding arch again.

You can sharpen your peeler using this method if:

Tips:

Different peelers

Peelers made of more flexible and better quality plastic with high arches over the blade often cost more than basic peelers. However, if the price is less than double, it still pays off. The blade-turning trick would mean that you can get two blade life-spans for the price of one, while enjoying using a better quality kitchen tool, usually with a mush better handle and better quality steel of the blade.

Fruit/vegetable peeler with an arch over the blade.
A so-called “Australian” peeler with a high arch over the blade. This peeler is made of strong yet flexible plastic, which makes it bendable and suitable for the quick sharpening described above.
Potato peeler with no arch over the blade.
This peeler is made of cheap, hard, brittle plastic and has no arch. It either doesn't bend, or breaks.

It is more practical to buy the peelers that have an arch and/or are made of flexible materials: they are easier to use because the peels fit freely through the arch, and they will last twice as long because you can turn the blade and make it sharp-like-new again. And, by buying and then throwing away fewer cheap peelers, you will reduce waste and help the environment.

Source:  annystudio.com