Hailing from Okinawa, the purple sweet potato, also known as beni imo, is a delightful potato used in many desserts. It is also quite healthy and is classified as a superfood.

Everyone knows that sweet potatoes are healthy. But there is another sweet potato that may rival the one you are used to seeing. It comes from Okinawa, Japan, and it is called Beni Imo, or the purple sweet potato.

What is Beni Imo?

It isn’t likely that you’ve seen the purple sweet potato in the United States unless you’ve shopped at a specialty grocer or Asian supermarket. But these healthy and delicious potatoes are considered a celebrity of the vegetable world in Japan. And especially Okinawa, where you can find a variety of beni imo sweets and ice cream on nearly every corner. Beni imo looks much like a regular potato, except for one vast difference —the flesh is a striking purple color. This color results from the same molecule that gives red cabbage or blueberries their deep, vibrant colors.

While Okinawa is well-known for cultivating many culinary treats and treasures, the purple sweet potato did not originate there. It was first brought to the archipelago by Noguni Sokan in the early 1600s. Noguni was a government official dealing in trade with China, where he first discovered the purple sweet potato.

Noguni brought the purple sweet potatoes back to Okinawa, where it grew very well. Within 15 years, many other parts of Japan began producing the potatoes. Today, it is known as the Okinawan sweet potato in the United States and other parts of the world.

Beni Imo — Your New Favorite Superfood

The same molecule in blueberries that has anti-cancer properties is also in purple sweet potatoes, which is why they are classified as a superfood. Beni imo also contains anti-aging and antioxidant properties and a large host of vitamins and minerals.

One purple sweet potato contains four times your daily recommended dose of Vitamin A and half of your daily Vitamin C requirement. Other vitamins and minerals in the sweet potato include copper, vitamin B6, potassium, and iron. The beni imo is also an excellent source of dietary fiber.

There are ongoing studies regarding the purple sweet potato for its anti-cancer, antifungal, and antibacterial properties. The vegetable also helps improve blood sugar levels and reduce the risk of cardiovascular disease. 

How to Cook with Beni Imo

While you can certainly cook purple sweet potatoes in many of the same ways as you would other potatoes, beni imo are very sweet and perfect as a dessert. In Japan, the potatoes are used to make everything from wagashi to cheesecake, bread and brownies, cakes and chocolates, and especially ice cream! And while you can only find some treats in Okinawa, you can indeed find plenty of recipes for flavorful desserts using the purple sweet potato on the Internet. In Asian supermarkets, it is also sold in powdered form, perfect for making confectionery and flavoring other desserts.

The skins of purple sweet potatoes are also edible, so there is no need to peel them unless a recipe calls for it. They do take longer to cook in the oven though — about 1 ½ – 2 hours at 350°. You can also boil, steam, or fry them to make colorful French fries.

Where to Buy Purple Sweet Potatoes?

They may be a bit more challenging to find, but your best bet is Asian groceries and supermarkets. You can also find them at now at many supermarkets that often carry larger varieties of vegetables when they are in season, during the fall and winter months. You can also order seeds online and grow them at home in your garden!

Some supermarkets might have them labeled as Hawaiian sweet potatoes, as they have grown in abundance since the climate is similar to that of Okinawa. There are also two primary varieties of purple sweet potato that you can usually findin stores in the United States. The Okinawan sweet potato has brownish-white skin similar to regular potatoes. The other kind has a purplish skin, making it easily identifiable as a purple sweet potato.

When buying purple sweet potatoes, look for those that are firm to the touch and absent of any brown spots, wrinkled skin, or sprouts.

How to Store Purple Sweet Potatoes

Beni imo are not as sturdy as other potatoes. Bruising them can cause the sweet potato to go bad rather quickly. Keep them at room temperature and consume them within a week. If you want to try storing them longer, keep them in the dark, cool place that is dry and well-ventilated. Don’t keep them in the refrigerator as that can ruin the flavor and make the center become very hard.

After cooking, you can store the beni imo dish in the fridge in an airtight container for up to a week. You can also freeze beni imo.