Purple Sweet Potatoes and How to Use Them

Every week we get Down & Dirty, in which we break down our favorite unique seasonal fruits, vegetables, and more.

Today: Keep your eyes peeled (get it? yeah, okay, you get it) for sweet potatoes in striking hues.

Despite what their name would suggest, sweet potatoes aren’t potatoes. They’re one of the few edible plants within the Morning Glory family -- maybe the only family member you actually eat, because really, how often are you eating water spinach?

Just like purple carrots, there are a number of varieties of purple sweet potatoes. These pictured are Stokes Purple sweet potatoes, and you’ll notice that not only is the flesh a shade of magenta purple (1, below), but the skin is purplish (2, below), too; this is opposed to some other purple sweet potato varieties, like the Okinawan sweet potato, which have more of a typical potato-beige colored skin.

Unlike a lot of other purple vegetables that lose their distinctive coloring when cooked, purple sweet potatoes will maintain their coloring, and the flesh of these Stokes Purple sweet potatoes will actually brighten!

Sweet potatoes are generally thought of as being one of two types: those that have soft, moist flesh and those that have firm, dry flesh, the latter of which can be more mealy and fibrous. (In case you're ever on Jeopardy!, know that there is a third type too though -- the boniato, or Cuban sweet potato.)

If you’re gearing up for candied yams at Thanksgiving, you're likely actually having the moist, soft-fleshed sweet potatoes -- yams are an entirely different vegetable. At one point growers in the U.S. started referring to the moist, sweet types of sweet potatoes as yams -- to distinguish them from the dry, firm varieties -- and the name stuck.

Sweet potatoes grow in tropical and subtropical regions around the world, so they can be grown in the U.S., unlike yams, which always come from a tropical locale. Stokes Purples are grown in California; in the U.S., sweet potatoes are grown in a handful of states, but are mainly found in subtropical Southern states like North Carolina, Mississippi, and Louisiana. If you live in an area where sweet potatoes are grown, head to a well-stocked farmers market to find sweet potato greens when they're in season -- the young vines and leaves of the plant are edible, and you can cook them as you would spinach or any other greens.

Sweet potatoes are generally available year-round, but Japanese varieties (like the Okinawan sweet potato) tend to be available from late summer through late spring. You have your best chance of procuring Stokes Purples from September through April: Check Frieda's website to see where you can find them near you.

As with all other potatoes and sweet potatoes, choose firm specimens. If you see any cuts, sunken spots, or signs of shriveling, choose a different potato. Diane Morgan also recommends selecting “medium-size roots that are plump in the middle (3) with tapered ends (4).”

Store them like you would regular potatoes -- in a basket, in a cool dry place -- but note that they have a shorter storage lifespan than regular potatoes, so plan to use them within a week or two.

You can use purple sweet potatoes anywhere you’d use orange sweet potatoes, but you might want to choose applications that highlight their color.

Keep it simple and serve them baked with butter, brown sugar, and spices, or mashed with maple and chipotle. Make purple potato chips, sweet potato gnocchi, or sweet potato fries. Use them in desserts like sweet potato pie or ice cream.

Tell us: How do you like to use sweet potatoes? What would you do with purple ones?

Photos by Mark Weinberg