This is a really great way to preserve sweet potatoes to use in casseroles or pie if you do not have a cellar.
Wash sweet potatoes that have been cured for at least one week. To cure sweet potatoes: store the fresh potatoes in a warm room in the house for 14 days. Curing develops the flavor and allows for longer storage.
Peel and cook the sweet potatoes until almost tender in water, steam, a pressure cooker, or the oven.
Let stand at room temperature until cool. Cut into chunks, slices, or mash.
To prevent darkening, dip whole sweet potato or slices for 5 seconds in a solution of 1/2 cup lemon juice to 1 quart water. To keep mashed sweet potatoes from darkening, mix 2 tablespoons of orange or lemon juice with each quart of mashed sweet potatoes.
Pack into containers, leaving 1 inch headspace. Make sure all the air is squeezed out of the bag. Seal and freeze.