Freezing any type of uncooked potato is a risky business because of the tendency of the water and the starch in the potato to separate. The typical result is watery, mushy potatoes when defrosted. A few tricks help mitigate the effects if you decide to freeze raw white potatoes.
Blanching Is Key
Uncooked potatoes, regardless of what type they are, freeze better when they have been blanched ahead of time. Choose freshly harvested small potatoes whenever possible, and clean them with the skins on. Blanch potatoes smaller than 1 1/2 inches in diameter for approximately four to six minutes, and larger ones as long as 10 minutes. Make sure the water is hot enough to heat the potatoes all the way through, to avoid discoloring of the centers. Drain the water and cool the potatoes before packing and freezing.