Before you toss the potato peels into the trash, look at the bottom of your cabinet. That old skillet with orange spots, the knife that sat wet in the sink, the baking sheet that started to rust in the corners: they may all have a second chance. More and more people mix potato peels with a little baking soda to clean them, and the trick is older than it looks.
What it’s for
The mix is used to remove light rust from kitchen metal: cast iron skillets, steel pans, baking sheets, knives, graters and old utensils. Instead of buying a rust remover, you use two things that are already in the kitchen, one of which usually ends up in the garbage.
Why does it work? According to Food Republic, the oxalic acid in potatoes helps dissolve rust, while baking soda adds a mild abrasive and lifts the residue away. In other words, the potato does the chemistry and the baking soda does the scrubbing, without scratching the metal the way a harsh product or a wire brush can.
How to do it
- Sprinkle a thin layer of baking soda over the rusty area.
- Press the potato peels on top, flesh side down. For a knife or a small utensil, you can also push the blade into a raw potato cut in half.
- Leave it overnight. The acid needs time to work on the rust.
- Scrub the next morning under running water, using the peel or half a potato dipped in baking soda like a brush. For stubborn spots, add a pinch of coarse salt for extra grit.
- Repeat if needed, then dry the piece immediately and completely.
The step most people skip
Drying is what decides whether the rust comes back. Never let cast iron air-dry: wipe it, then put it on a warm burner for a minute or two to drive out the last drops of water.
Cast iron also needs its protective layer back. After any rust removal, rub a very thin coat of cooking oil over the whole pan, inside and out, and bake it upside down. Bob Vila recommends about a tablespoon of oil and one hour at 350°F, then letting it cool completely before use. Food Republic suggests a hotter oven, 450 to 500°F, for a harder finish. Either way, the pan comes out darker and better protected.
The limit
This is a trick for light, surface rust. If the rust covers most of the pan or has left deep pits in the metal, a potato won’t be enough: a longer soak in equal parts white vinegar and water, followed by fine steel wool, is the next step, and deeply pitted pieces may not be worth saving. And don’t cook on rust: scrub it off first.
It costs nothing to try, though, and it gives a second life to peels you were about to throw out. Potatoes also deserve better than the bottom of a bag: here’s how to store them so they don’t sprout. Rust on garden tools is a different story, as this permaculture gardener shows. And baking soda has another well-known partner in cleaning: hydrogen peroxide.
A few peels, a spoonful of baking soda and one night. That’s the trick.
