How to Store Sweet Potatoes

Freshly dug sweet potatoes are subject to rapid spoilage because their skins are quite thin and are easily damaged. They should be handled with care.
If you plan to use fresh potatoes within a month or two, then you should simply air-dry the tubers for 7-10 days at 75-80F (24-27C).
After drying them, store at 12-15°C (55-60°F) in a cool dry place such as pantry, cellar or garage for 1-2 months.

Store-bought potatoes are cured so they have a thicker skin than freshly dug potatoes. Technically they can last for up to 12 months if stored under the right conditions (temperature and humidity)
Don’t wash potatoes until you’re ready to cook them as moisture will hasten spoilage.
Store sweet potatoes at 12-15°C (55-60°F) in a cool dry place such as pantry, cellar or garage for one month or longer. (depends on when they were cured)
If you store potatoes at room temperature, (23-25.5°C; 73-78°F), then you should use them within one week.
Never store sweet potatoes in the fridge because they may develop a hard core and an off taste.
Cooked, sliced or mashed sweet potatoes, can be frozen. Add a little lemon juice to keep them from darkening. Pack in airtight freezer containers.

Sweet potatoes are traditionally cured to improve storage period, flavour and nutrition.
How they are cured: freshly dug roots are dried on the ground for 2-3 hours then cured (stored) at 29-32C (85-90F) and 85-90% relative humidity for 4-7 days. This makes them develop a thick protective skin. It also improves their sweetness.
Cured sweet potatoes can keep for up to 12 months at 13-15C (55-59F) and 85-90% relative humidity.