Sweet potato curing is a short period of controlled warm, humid conditions that improves the quality and longevity of harvested roots. This process serves three primary functions. It allows wounds sustained during harvest to heal, forming a protective layer that prevents decay and dehydration during storage. Curing also triggers the conversion of starches into sweet, complex sugars, significantly improving flavor. This conditioning also toughens the skin, making the sweet potato more resistant to post-harvest diseases and enabling long-term storage.
Harvesting and Initial Preparation
Sweet potatoes require a long growing season, typically 90 to 120 days after planting, resulting in a late summer or early fall harvest. You can check for readiness by gently probing the soil near the plant’s crown to feel for large, firm tubers, as the leaves may not always die back in the warm Florida climate. Roots must be dug before soil temperatures fall below 55°F; lower temperatures cause chilling injury and an unpleasant bitter flavor.
Digging must be done with care to prevent physical damage, which compromises curing success. Use a digging fork or shovel to lift the roots, inserting the tool far away from the plant’s crown to avoid accidentally slicing or bruising them. Freshly harvested roots have thin, easily damaged skin, so they should be handled gently and never pulled directly from the vine.
After lifting, allow the roots to dry on the ground for a few hours. Do not wash the roots, as introducing water increases the risk of rot during curing. Instead, gently brush off any large clumps of soil once the roots are dry. Severely damaged, cut, or diseased tubers should be set aside for immediate consumption or discarded, as they will not cure properly and may spoil others.
Creating the Curing Environment
Curing sweet potatoes requires maintaining a specific environment of high heat and high humidity. Ideal conditions are 85°F to 90°F and 85% to 95% relative humidity. This environment must be maintained for a period of four to fourteen days, with the exact time depending on how consistently the temperature is held within the ideal range.
Achieving these conditions in Florida requires creating a controlled, enclosed space, as ambient temperatures fluctuate and humidity may be insufficient. A small, insulated room, closet, or even a large cooler or cabinet can be used as a curing chamber. The goal is to set up a system that can reliably generate and hold the required heat and moisture.
Heat can be supplied with a small space heater or a heat lamp directed away from the roots. To boost the humidity, which is necessary for the roots to heal, you can place a bucket of water or a few wet towels in the chamber near the heat source, or employ a small humidifier. A thermometer and a hygrometer must be placed inside the chamber to continuously monitor and adjust the environment.
Post-Cure Storage Requirements
Once the curing period is complete, the sweet potatoes must be quickly moved from the hot, humid environment to a cool, dry location for long-term storage. Storage is a long-term cool-down designed to preserve the cured state. The ideal storage environment is 55°F to 60°F and 60% to 70% relative humidity.
The lower temperature slows the respiration rate, preventing sprouting and excessive moisture loss, while moderate humidity keeps them from shriveling. Avoid storing sweet potatoes below 50°F, as this causes chilling injury, resulting in hard centers, off-flavors, and increased susceptibility to rot. Refrigeration is never recommended.
For Floridians, finding a spot that maintains the 55°F to 60°F range can be a challenge outside of winter. Suitable locations may include a cool pantry, a closet on an interior wall, or an insulated garage. Properly cured roots should be stored in ventilated containers, such as slatted crates or cardboard boxes, and can last six to twelve months under optimal conditions.