Weeknight gratin, homemade mash, or party-sized potato salad are quicker and easier if you peel the potatoes in advance. The only problem: once peeled, potatoes change color from white to a pinkish gray—not exactly appetizing. The solution is as simple as a bowl of water.
Why Do Peeled Potatoes Change Color?
When you cut into the flesh of a potato, its cell walls break down, exposing its phenols and enzymes to the air. This oxidation causes the pink or gray discoloration. But the color change doesn’t make the potato dangerous to eat.
Soak the Taters
A simple way to prevent oxidation is to place the cut pieces into a bowl of cold water; the potatoes must be completely submerged. The water reduces the cut potatoes’ exposure to oxygen, stalling discoloration. Place this bowl of soaking potatoes in a refrigerator for up to 24 hours; any longer, and the potatoes’ quality and color will start to deteriorate.
Add a Little Acid
Add a small amount of acid to the water to further discourage discoloration. For every gallon of water, use 1 tablespoon of lemon juice or vinegar. This little bit of acid won’t affect the taste of the potatoes once they’re cooked, but it could make them extra crispy if you plan to roast or fry them.
Using the Potatoes
Even if you’re boiling the potatoes, drain them first. Starch accumulates in the soaking liquid overnight, and cooking the potatoes in this water could make them gummy—especially if you plan to mash them. For fried potatoes, hash browns, or roasted potatoes, dry potatoes thoroughly before using so they don’t steam as they cook. Dry potatoes become delectably crunchy on the outside and soft and fluffy on the inside.