The humble sweet potato is both delicious and nutritious. It’s also not actually a potato at all.
Harold McGee wrote in “On Food And Cooking” that the root vegetable native to northern South America is the “second most important vegetable worldwide.” And according to Lisa Kingsley in EatingWell, “Sweet potatoes are one of the most nutrient-dense vegetables in the world.”
In the United States, they are grown primarily in North Carolina and Louisiana, and while the sweet potato is a staple in grocery stores year-round, they are at their best in fall and early winter.
Here’s what you need to know about this terrific root tuber.
-— Types of sweet potatoes
Sweet potatoes come in a variety of colors, both inside and out. Their skins can be various shades of brown, yellow, orange, red or purple. The flesh varies, too, and can be creamy white, vibrant orange or deep purple.
The varieties can be broken down into two categories: firm and soft. Firm sweet potatoes typically have thin skins and pale flesh, and, unsurprisingly, will remain firm when cooked. Soft varieties encompass the ones you typically purchase at the store, with a thick copper skin and bright orange flesh. They are called “soft” because they retain much of their moisture when cooked, leading to a creamier interior.
Here are a just a few that you might come across:
Beauregard. Though the name might give off an air of poshness, this is the most common variety in the United States. “Beauregards have purplish-red skin and a deep orange interior,” Elazar Sontag wrote for Serious Eats. “Their flesh is slightly stringier and more juicy than some other varieties when cooked, so they’re good for mashing and incorporating into baked goods and desserts.” And while this is certainly the case, they are also a great all-purpose sweet potato.
Jewel. These have a lighter skin than Beauregards and a similarly colored flesh. Flavor-wise, they are slightly less sweet than the most produced variety, but the two are interchangeable when it comes to recipes, be it for a holiday casserole, quesadilla-pizza hybrid or a quick hash.
Garnet. Named for their red-purple skin, this variety is easy to spot. Similar to the previous two, garnets have a bright orange flesh. However, “They’re even more moist than jewels or Beauregards, which makes them great for baking projects,” Sontag wrote.
Murasaki. These Japanese sweet potatoes have a reddish-purple skin and white flesh. This is one of the “firm” varieties that is drier than the orange-fleshed varieties. When cooked, their texture is much closer to that of a regular potato than soft sweet potatoes.
Okinawa. These sweet potatoes typically have a dusty tan skin that conceals a bright purple flesh that adds much aesthetic appeal to whatever dish they’re used in. Like white-fleshed sweet potatoes, purple-fleshed varieties also fall into the firm camp.
— Sweet potatoes vs. yams
Perhaps my biggest culinary pet peeve is calling a sweet potato a “yam.” True yams and sweet potatoes are completely different foods, and most people in the United States have never actually encountered the former. (Even as a culinary professional, as far as I can recall, I have not.) “True yams are the starchy tubers of tropical plants,” McGee wrote. “They are seldom seen in mainstream American markets.” The ones that you can find here tend to be imported from the Caribbean and have a rough, bark-like skin.
The confusion stems from marketers in the 1930s. Up until that point, only the firm, white-fleshed varieties of sweet potatoes were grown in the United States. But when the soft, orange-fleshed root tubers were introduced, farmers wanted a way to differentiate between the two and started using the term “yam” to identify these new vegetables. The impact of that decision has entrenched itself in society’s vocabulary to this day, with “yams” for sale across the country and recipes for dishes such as candied yams spiking in popularity every Thanksgiving.
I’m all for language evolving over time, but I don’t support designating a word for a new-to-you item when that word already describes something completely different. So the candied sweet potatoes at my holiday table answer to their real name.
— Selection and storage
When shopping for sweet potatoes – after you’ve decided whether you want a soft or firm variety – you should look for ones that have a smooth, taut skin and are free of soft spots, bruises, cracks or signs of sprouting. It’s best to avoid the sometimes gargantuan specimens you might come across, as smaller sweet potatoes (in the 4- to 8-ounce range) tend to be less starchy and moister than larger ones.
Sweet potatoes keep best in a cool, dark storage space that is held at around 50 degrees, and they can last for three to six months there. But unless you have such a cellar, they are best kept at room temperature in a dark space and should be consumed within a week or two. (Sweet potatoes should not be kept in a refrigerator as they can dry out and develop an unpleasant flavor.)
When you’re ready to cook, scrub the sweet potatoes under cool running water with a produce brush. You can leave the peel on for more nutrition or remove it with a vegetable peeler, but otherwise they’re ready to roast, fry, mash, steam or use however else you decide.