Peeled raw potatoes can stay in water in a refrigerator for approximately 24 hours. The peeled potatoes should be completely submerged in a big container or pot of very cold water.
To make sure the potatoes stay submerged in the water, one can place a cover over the potatoes in the container. So potatoes do not absorb too much water in the refrigerator, one can keep them whole and then cut them when they are ready for use. To avoid potatoes from discoloring, one also can add some lemon juice or vinegar to the water before storing them in the refrigerator.
Storing peeled potatoes overnight in a refrigerator is a good idea when cooking for a large group or a big holiday such as Thanksgiving. However, before storing potatoes, one should clean and peel them carefully.