Here is a guide to the most popular types of sweet potatoes, which also includes the often confused yam. Learn about the many texture and flavor differences when adding creaminess and natural sweetness to recipes.
Table of Contents
- Red Garnet
- Japanese White (Satsuma-Imo, Kotobuki, or Oriental)
- Murasaki (Japanese Sweet Potatoes)
- Okinawa (Hawaiian Sweet Potatoes)
- Stokes Purple
- How do they become sweet?
- Difference between yams and sweet potatoes
- Selecting and storing
- Health benefits
- Take home message
Sweet potatoes are root vegetables prized for their starchy texture, earthy, and natural candied flavor. You may have grabbed a few to make sweet potato casserole or a decadent pie for the holidays. However, their culinary applications are versatile, and you can enjoy them year-round. The possibilities are endless, from baking, roasting, frying, steaming, and boiling to making savory or sweet dishes!
Scientifically known as Ipomoea batatas, these fleshy roots are members of the Convolvulaceae or morning glory family. There are many varieties than just the typical red-skinned ones piled up next to the russets at the grocery store. Plus, you may be surprised to find that what you think are yams aren’t. They are actually varieties of sweet potatoes labeled as yams, which causes plenty of confusion.
The most common sweet potato sold at grocery stores. It is the gold standard potato in the United States. The skin is reddish, and the flesh is bright orange and is the sweetest for orange types. The slightly stringy, soft, and moist texture makes it great for mashing into a puree for pies or casseroles or holding their shape when roasted into fries.
It has copper skin and light orange flesh, very similar to the Beauregard. It has a more robust flavor, but not as sweet, with a soft and moist texture. Great for casseroles, mashes, pies, baking, and roasting.
This deep reddish-orange skin and bright orange flesh has a more savory taste and is the least sweet compared to other varieties. It also can be higher in moisture level, giving a softer texture. Great for mashing into a puree for casseroles, baked or roasted, or used for dessert that has added sweeteners.
The orange-colored skin with speckled dark brown spots has a malty sweetness. The texture is moist and creamy, a favorite variety in the South to make casseroles and desserts or just slice and roast.
Copper orange skin and bright orange flesh. Sweet with a moist texture, also known as Baby Bakers. Great for baking and slicing for fries.
The red skin and moist orange flesh, sweeter compared to Beauregards. Bake, roast, or dice for soups and stews.
Their tan skin and cream-colored flesh have a slightly sweet taste. The texture is more firm and dense yet creamy. Good for mashing, boiling, roasting, baking, soups, and stews.
The tan-colored skin with white flesh is moderate in sweetness. The dry texture works well for keeping its shape when made into fries and is added to soups, stews, and curries.
Japanese White (Satsuma-Imo, Kotobuki, or Oriental)
Beneath the dark purple skin, there is a creamy yellow flesh that gets deeper in color when cooked. This variety is very sweet, starchy, dense, and moist. It has a lovely chestnut flavor, with a smooth and velvety texture—great baked, roasted, or steamed.
Murasaki (Japanese Sweet Potatoes)
Originated in Louisiana and primarily grown in California. A reddish-purple skin with white flesh that turns golden in color when cooked. Very sweet in flavor with vanilla, brown sugar, and nutty notes. The texture is starchy and moist. Great for roasting or mashing and adding to casseroles or desserts.
With a smooth, tan-colored skin and ivory flesh, as it cooks, the color gets more golden. The texture is firm, dense, and dry, similar to russet potatoes, with a light sweetness. Good for mashing, roasting into cubes, making into fries, or frying for the lower amount of sugar.
Pale yellow skin and white flesh. Grown in the Caribbean, it has a mild sweetness and starchy flavor. Great for boiling, mashing, or adding in chunks to soups and stews.
Okinawa (Hawaiian Sweet Potatoes)
The tan outer skin isn’t impressive until you cut open and see the gorgeous purple flesh. The dark pigments make this variety one of the healthiest. The texture is more dense, dry, and mealy, with a sweet and nutty flavor. Often used in Japanese desserts or Hawaiian dishes, it can be roasted, baked, boiled, steamed, or added to soups, stews, and braises.
Cultivated in North Carolina, the light purple skin reveals a deep purple flesh. It has a mildly sweet taste, floral notes, and a more firm and dry texture. Suitable for baking, boiling, and steaming.
How do they become sweet?
After harvesting, the sweet potatoes can be sold right away, called a green crop, or cured for about 1 week. The curing process is done at a warm temperature of 85ºF and 95% relative humidity. This short process reduces microbial decay during storage, heals many wounds on the skin’s surface, makes them more resistant to shrinking, and it makes the flesh sweeter to a point.
The warm conditions encourage the amylase enzymes in the flesh to break down some of the starches; amylose and amylopectin into simple sugars. Storing can allow about 27% conversion while cooking between 140 to 170ºF increases enzyme activity to convert about 75% of the starches to the sugar maltose. Who knew the potatoes could get even sweeter by simply cooking!
Difference between yams and sweet potatoes
Often the term is used interchangeably, especially at the market. True yams are not sweet potatoes and they are actually very difficult to find at most grocery stores. Yams are found mainly in Asia, Africa, South America, and Southern parts of the United States. They have very thick, bumpy, fibrous brown skin and cream-colored that looks similar to yucca.
Selecting and storing
When selecting a sweet potato, pick one up and make sure it feels firm and has no big cracks. It’s best to store in a cool, dark place, ideally 55 to 60ºF, for long-term storage of about 2 to 4 weeks. At room temperature, when it’s a bit warmer, eat within 1 to 2 weeks for the best taste. Do not store it in the refrigerator. They begin to taste bitter. The center will also harden below 55ºF, where the enzyme pectin methylesterase activates and strengthens the cell walls for an undesirable firm texture that stays during cooking.
What about a sprouted sweet potato? They are still safe to eat. Just use a paring knife or vegetable peeler to remove the small spouts. However, toss out ones that are wrinkling and have soft spots.
They may taste like dessert, but these tubers are packed with nutrition. The orange flesh is high in Vitamin A, and the purple-fleshed varieties have more antioxidants due to their phytonutrient-rich dark pigment. The roots are low in fat and glycemic index, making for an attractive carbohydrate choice.
A one-cup serving provides almost 114 calories, 2 grams of protein, 27 grams of carbohydrates, 4 grams of fiber, insignificant amounts of fat, and various vitamins and minerals like vitamin C, calcium, and magnesium. A great starchy vegetable to add to your diet.
Take home message
The main types of sweet potatoes are characterized by their colored flesh, commonly orange, white, and purple, or the hue of their skin. Each variety has differing sweetness levels and other flavor notes like pure sweet, nutty and roasted, to molasses. There is also a big texture difference, typically soft and moist for the orange types or firm and dry for white and purple.