From pressure-canning to freezing and dehydrating, sweet potatoes can be preserved for storage in a variety of ways. Each method comes with its own benefits: frozen sweet potatoes can last several months, while dehydrated sweet potatoes make for a sweet, crunchy snack at any time. Properly storing sweet potatoes helps them retain their flavor and fresh appearance.
Store sweet potatoes in a cool, dark place, such as a basement or unheated garage, for up to two weeks. Don't store them in the refrigerator, though, as this can affect their flavor and cause them to decay more quickly. Sweet potatoes are often confused with, or labeled as, yams; however, true yams are grown not in the U.S. but in Africa and Asia, where they are prized for their hardiness. Ranging in size from a few inches to more than 5 feet long, yams can be stored for up to six months provided they're protected from rain and direct sunlight. Yams are often stored on shelves or in yam barns.
All Dried Up
Dehydration preserves sweet potatoes for storage. You can use this method to turn them into crunchy chips. Sweet potatoes can take from two to 19 hours to dehydrate completely. When the sweet potato is cut, and no moisture appears, the process is complete. Once the sweet potatoes are completely dehydrated, store them in an airtight container in a cool, dry place.
Sweet potatoes can also be pressure-canned for storage. Boil or steam small or medium sweet potatoes for up to 20 minutes, or until they're soft, then peel off the skins and cut them into uniform chunks. Fill jars with the sweet potatoes but not all the way; leave a 1-inch space at the top. Cover the sweet potatoes with boiling water, taking care to leave the 1-inch space empty. Sweet potatoes should not be dry-packed. In a dual-gauge pressure canner, process the sweet potatoes at 11 pounds of pressure. If you're using a weighted-gauge pressure canner, process the sweet potatoes at 10 pounds of pressure.
Freeze sweet potatoes for prolonged storage. The National Center for Home Food Preservation suggests cooking the sweet potatoes until they're almost tender, as raw sweet potatoes don't store well once they're cut. Then, mash, cut, slice or peel the potatoes. To prevent darkening, add 2 tablespoons of lemon juice to each quart of sweet potatoes; dip the potatoes in the lemon juice if they're not mashed. Pack the sweet potatoes into containers -- leaving ½ inch of space at the top -- seal the containers and place them in the freezer. Store them for up to three months.
Skin and Spoilage
Check the sweet potatoes for spoilage. Signs of rotting sweet potatoes include soft spots, sprouting or mold on the skin. The skin can appear black in color when a sweet potato is rotting. Prevent raw, cut sweet potatoes from becoming discolored by placing them in a bowl of cold water until you're ready to use them.