What Are Sweet Potatoes?

Sweet potatoes are the root of a vine in the morning glory family and native to Central America or South America. The vegetable's history dates back thousands of years, cuttings of the vine plant transported by the Polynesians to various islands as well as New Zealand. Sweet potatoes are now grown in warm, moderate climates across the globe, including Asia, America, South America, and Africa.

 Often mistakenly called yams, sweet potatoes are root vegetables that can range in color from orange to purple to white. The root and leaves are both edible, but the root is most commonly sold and eaten. Much like their distant cousin potatoes, sweet potatoes are often cooked before they are consumed.

If you live in America, whether the tag says sweet potato or yam, chances are you're buying a sweet potato. In the 1930s, Louisiana growers started labeling their sweet potato crops as yams to distinguish them from competitors, and confusion has lingered ever since. Yams are actually a totally different plant, native to Africa and popular in West African and Caribbean cuisine. The root vegetable has a brown, rough peel similar to a tree trunk, and the tubers can be small or up to five feet long. The flesh is white or purple, starchy, and lacks sweetness, and they're not commonly sold in the U.S. If you're looking for actual yams, they can sometimes be found in specialty grocers.

The most commonly cultivated sweet potato is the Beauregard, an orange-fleshed variety with a dull red peel. It's a versatile veggie, good for roasting, baking, boiling, frying, and more. Jewel and Garnet are also popular orange sweet potatoes, with Jewel covered in a dull copper skin and Garnet wearing a red-purple skin. There are also white sweet potato varieties, which tend to be milder, less sweet, and drier. These types are good for mashing for frying. Purple sweet potatoes are typically best baked to prevent drying out and have a lightly sweet taste and colorful interior.

There are even varieties that mix and match colors, sporting white peel and orange flesh or purple peel and speckled interior. The varieties are all similar in taste in texture, with minor variations in flavor and moisture.

Since sweet potatoes grow in the dirt, they should be scrubbed thoroughly before cooking. The root vegetables can be baked, steamed, or microwaved whole. They can also be sliced or chopped and roasted, boiled, or fried. The peel is edible but can be removed will a peeler or knife if desired.

Sweet potatoes can even be consumed raw—they don't contain the dangerous enzyme solanine as raw regular potatoes do. Eaten raw in large quantities, raw sweet potato can make digestion difficult, but added in small quantities to dishes like a fresh smoothie, they add good nutrition without any issue.

When cooked, sweet potatoes have a mild, starchy, sweet flavor. When baked or boiled, the flesh becomes soft and slightly stringy (depending on the variety). When fried or roasted at high heat, the exterior becomes crisp and caramelized. They're mild, sweet flavor makes the vegetable a popular ingredient in a variety of dishes.

Sweet potatoes are commonly prepared like regular potatoes—baked whole. Topped with butter, sour cream, and/or brown sugar, they make a tasty sweet or savory side dish. But the naturally sweet root vegetable is just as versatile as a potato, forming the base of soups, roasts, and pastas. Sweet potatoes are especially popular in the American south, where they are mashed and used to make casseroles and pies. The tuber also makes excellent fries and chips.

• Classic Sweet Potato Casserole
• Crispy Fried Sweet Potato Fries
• Mississippi Sweet Potato Pie

Sweet potatoes are in season in the winter but are available at supermarkets year-round with no marked difference in quality. More interesting varieties can sometimes be found in specialty stores and at farmers' markets while in season. Sweet potatoes can also be found canned and sometimes frozen.

Look for potatoes with tight skin and firm flesh, without wrinkles, cuts, or bruises.

Sweet potatoes are best stored at room temperature in a basket or open paper bag. In a dry, dark, cool place, they can last up to three weeks. If your kitchen has less than ideal storage conditions, plan on using sweet potatoes within a week. The vegetable will shrivel up and become soft as it goes bad.

Cooked sweet potatoes can be stored in the refrigerator in a covered container for up to four days. Cooked whole, sliced, cubed, or mashed sweet potato can be frozen for up to six months. Raw, cubed sweet potato can be frozen for up to three months.

Sweet potatoes have 20 grams of carbs per 100-gram serving, largely from starch. This makes them a filling addition to any meal. They also contain 3 grams of dietary fiber and almost zero fat. Sweet potatoes are very high in vitamin A, providing 89% of the recommended daily value per 100-gram serving, and orange varieties are high in beta-carotene, believed to be beneficial in maintaining eyesight.