In order to freeze raw potatoes, the potatoes must first be blanched. Before blanching, peel the potatoes, or scrape and wash them. To blanch the potatoes, place them into a blanching basket, and lower them into water that is boiling vigorously. Next, put the lid on the blancher. Within one minute, the water should return to boiling. If this does not occur, there is not enough water. Be sure to use 1 gallon of water per pound of potatoes.
Once the water returns to a boil, start keeping track of time. Blanch the potatoes for three to five minutes, depending on their sizes. Take care to avoid over-blanching or under-blanching the potatoes.
Next, cool the potatoes in ice water for 5 to 10 minutes, and then drain. Pack the potatoes into containers, allowing 1/2 inch of headspace. Seal the containers, and then place them in a freezer. For taste and quality, store frozen potatoes no longer than 12 months. Frozen potatoes fare best when stored in a deep freezer that keeps the potatoes completely frozen and does not have thaw cycles.
Blanching prevents the potatoes from losing flavor, color and texture. It also prevents the potatoes from losing vitamins, and it cleanses the surfaces of the potatoes.