How to prevent potatoes from oxidizing when peeling?

Thursday 10 July 2025 21:00 - Patricia González
How to prevent potatoes from oxidizing when peeling?

Sometimes, by going ahead of time, you end up going the long way. Like the other day, when I peeled the potatoes to make a Spanish tortilla, thinking of bringing forward the next day's meal. I left them in a bowl and went on with my business. But when I returned to the kitchen, they were no longer the same: they were gray, dull, with dark spots. As if they had been there for days. That clean, appetizing look of freshly peeled potatoes was gone.

I wondered what had happened: had they gone bad, could I still use them, or was it better to throw them away? Luckily, I found out why potatoes take on that grayish, unappetizing hue after peeling... and the best part is that it has a solution, and it's not complicated at all.


Why do peeled potatoes rust?

What happens has a name: oxidation. And understanding it helps prevent peeled potatoes from losing their good looks prematurely. As soon as you remove a potato's skin, you expose the inside to air. And that triggers a natural reaction: enzymes called polyphenol oxidases come into contact with oxygen and cause the surface to darken.

This is not dangerous and does not affect the safety of the food, but it does make it less palatable. And when that potato is going to be the base of a Russian salad, a Spanish tortilla or potatoes with seasoning, color matters.

So they have to be peeled just before cooking?

In an ideal world, yes, but we don't always have that margin. Sometimes we need to leave things prepared the day before, advance steps or have everything ready so we don't have to rush. The good news is that you can do it without visually spoiling the potatoes. You just need to apply this basic trick.

The trick that works



Soak them in cold water and store them in the refrigerator. It's that simple. As soon as you peel them, place them in a bowl of cold water and put it in the refrigerator. This easy gesture blocks contact with air and slows down the oxidation reaction.

  • If you leave the potatoes whole and peeled, they can last several days without problem.
  • If they are already cut, the ideal is to use them within 24 to 48 hours. And in this case, it is advisable to change the water once or twice a day to keep them fresh and prevent them from becoming laden with odors.

This little habit has saved me more than one meal: to have the potatoes ready for an omelet on a rushed day, to prepare the base of a salad when I have guests, or simply to organize my week better.

If you peel the potatoes in advance, soak them in cold water and store them in the refrigerator. This way you avoid them to darken and you don't have to give up to organize yourself well in the kitchen. A simple and effective solution.




Do you have any tricks you use to keep them from turning brown? Share it in the comments. We love to read your experiences and tips!

Patricia GonzálezPatricia González
Passionate about cooking and good food, my life revolves around carefully chosen words and wooden spoons. Responsible, yet forgetful. I am a journalist and writer with years of experience, and I found my ideal corner in France, where I work as a writer for Petitchef. I love bœuf bourguignon, but I miss my mother's salmorejo. Here, I combine my love for writing and delicious flavors to share recipes and kitchen stories that I hope will inspire you. I like my tortilla with onions and slightly undercooked :)

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