If you have ever attempted to store a peeled potato only to have it turn brown, you have experienced oxidation. Oxidation occurs when peeled potatoes are exposed to air and light. While it is safe to eat browned potatoes, it does not make for the most visually appealing dish. To avoid oxidation, it is best to use potatoes immediately after peeling; however, this is not always an option. If you must store peeled potatoes, there is a simple solution to keep them from turning brown.
Place the peeled potatoes in a bowl. Choose a bowl that is large enough to accommodate the potatoes and allows for at least an inch of water above the potatoes.
Add cold water to the bowl. Add enough water to completely submerge the potatoes. Add the 2 teaspoons of vinegar to the water.
Cover the bowl with a lid or cling film. Place the bowl in the refrigerator. Refrigerate the potatoes until you are ready to prepare them.
You may substitute the vinegar for 4 tablespoons of fresh lemon juice. Use the potatoes as soon as possible to prevent them from absorbing excess water. This can cause the potatoes to lose some of their flavour. Simmer peel potatoes that have turned brown in milk to turn them white again.