What is the difference between Okinawan sweet potatoes and purple sweet potatoes?

October 29, 2025 •

4 min read

While all purple-fleshed sweet potatoes get their color from powerful antioxidant compounds called anthocyanins, the Okinawan sweet potato is a distinct variety known for its beige skin and sweet, dry texture. This sets it apart from other purple sweet potatoes, such as the Stokes Purple®, which have purple skin. Understanding these differences helps in selecting the right variety for your next culinary creation.

Quick Summary

This article explores the differences between Okinawan sweet potatoes and other purple varieties, detailing their distinct characteristics, origins, taste profiles, textures, and nutritional value. It clarifies common confusion between these root vegetables and Filipino ube.

Key Points

Skin and Flesh Color: Okinawan sweet potatoes have beige skin and bluish-purple flesh, while other varieties like Stokes Purple® have purple skin and purple flesh.
Texture Profile: Okinawan sweet potatoes are known for their dry, starchy texture when cooked, whereas other purple varieties can be moderately to quite moist.
Flavor Notes: The Okinawan variety is mildly sweet with honey notes, while others might have floral or nutty undertones.
Origin and Cultivation: The Okinawan sweet potato originated in the Americas but is famously cultivated in Okinawa and Hawaii, while other varieties like Stokes Purple® were developed in the US.
Nutritional Value: All purple-fleshed sweet potatoes are rich in anthocyanins, powerful antioxidants that contribute to their color and health benefits.
Culinary Application: Okinawan sweet potatoes are well-suited for mashing and frying, while moister purple varieties can be excellent for savory soups and curries.
Not to be Confused with Ube: Unlike purple sweet potatoes, ube is a purple yam native to the Philippines, which has a distinct flavor, texture, and is sold mostly as an extract or jam.

The world of colorful root vegetables can be surprisingly complex, with many varieties often grouped under the general term “purple sweet potato.” A common point of confusion revolves around the Okinawan sweet potato, a specific cultivar with its own unique traits. While the Okinawan sweet potato is indeed a type of purple sweet potato, its characteristics, origin, and culinary uses set it apart from other varieties, like the American-cultivated Stokes Purple® or the Filipino purple yam, ube. Acknowledging these differences is key for home cooks and nutrition enthusiasts seeking specific flavors and textures.

What is an Okinawan Sweet Potato?

Despite its name, the Okinawan sweet potato (also called beni imo or Hawaiian sweet potato) actually originated in the Americas and was introduced to Okinawa, Japan, in the 17th century. It is a staple food in the Okinawan diet, a key factor in the region's famed longevity. The tuber has a creamy, beige-colored skin that often looks unassuming, but reveals a striking bluish-purple flesh when cut open.

Characteristics of Okinawan Sweet Potatoes

Exterior: Features a pale, off-white, or beige skin.
Interior: Has a deep, vibrant, bluish-purple or magenta-colored flesh.
Flavor Profile: Mildly sweet with hints of honey.
Texture: Possesses a very dry and starchy texture when cooked, which can become creamy when mashed.

What are Purple Sweet Potatoes?

"Purple sweet potato" is a broad term that includes many cultivars, including Okinawan and Stokes Purple®, which is a commercially cultivated variety in the United States. Most varieties trace their origin back to the Americas before being spread across the globe. Their distinguishing deep purple hue is due to a high concentration of anthocyanins, potent antioxidants also found in blueberries.

Characteristics of Other Purple Sweet Potatoes

Stokes Purple®: This variety has purple skin and a deep purple flesh that intensifies when cooked. It has a moderately starchy and somewhat moist texture, with a mildly sweet flavor and slight floral notes.
Molokai Purple: Cultivated in Hawaii, this variety has both purple skin and purple flesh. It is known for its moist, sweet flesh with a nutty, chestnut-like undertone.
Murasaki: Also known as the Japanese sweet potato, this type has reddish-purple skin but white flesh. It is sweeter and moister than the Okinawan sweet potato.

Culinary and Nutritional Differences

Beyond their appearance and origin, the varieties differ in how they are best used in cooking and their specific nutritional makeup.

Comparison Table: Okinawan vs. Common Purple Sweet Potatoes


Feature	Okinawan Sweet Potato	Other Purple Sweet Potatoes (e.g., Stokes Purple®)
Skin Color	Beige or off-white	Purple or reddish-purple
Flesh Color	Bluish-purple	Deep purple
Taste	Mildly sweet, hints of honey	Mildly sweet, floral or earthy notes
Texture	Dry, starchy; becomes creamy when cooked	Moderately moist or moist
Best for...	Mashing, frying, baking	Baking, stuffing, soups, curries
Antioxidant Content	High levels of anthocyanins; a major food in the longevity-linked Okinawan diet	Also rich in anthocyanins
Glycemic Index	Lower GI than many other sweet potatoes, but higher than orange varieties	Varies by variety and cooking method; some may have higher GI

The Misconception with Ube

Another point of confusion is the comparison to ube, a purple yam from the Philippines. While ube is a different species entirely and not a sweet potato, it is often confused with purple sweet potatoes due to its similar color. Ube has a much thicker, bark-like skin and a sweeter, more vanilla-like flavor. Unlike purple sweet potatoes, fresh ube is rarely available in the US and is typically sold as a powder, extract, or jam.

Cooking Applications and Flavor Nuances

The distinct textural and flavor differences mean these potatoes shine in various dishes. The starchy, dry nature of the Okinawan sweet potato makes it ideal for mashing or frying. Many enjoy it simply steamed, with its creamy sweetness as the star. In contrast, the slightly moister Stokes Purple® variety is a great choice for savory applications like soups and curries, where its floral notes can add complexity. Both can be used in desserts like pies, mochi, and ice cream. The key is to match the potato's qualities to the desired outcome of the dish.

Conclusion

While they may be lumped together as "purple sweet potatoes," Okinawan and other purple sweet potato varieties have distinct differences in their appearance, taste, and texture. The Okinawan sweet potato is known for its beige skin and dry, starchy purple flesh with a honey-like flavor, and is a staple of the Okinawan diet. Other purple varieties, such as Stokes Purple®, have purple skin and varying textures and flavor profiles. Both are celebrated for their high anthocyanin content and nutritional benefits, offering cooks a versatile and healthy ingredient. By understanding the specific characteristics of each, you can make an informed choice and appreciate the nuances that each tuber brings to a dish.

Learn more about sweet potato varieties and their culinary applications here: A Field Guide to Sweet Potato Varieties (and the Dirt on Yams).

Frequently Asked Questions

The term "purple sweet potato" is a broad category that includes the Okinawan variety. However, the Okinawan sweet potato has distinct characteristics, such as beige skin, a dry texture, and a mildly sweet flavor with honey notes, which differentiates it from other purple-fleshed varieties.

Okinawan sweet potatoes are notably drier and starchier compared to other varieties like Stokes Purple®, which have a moister, softer texture. When cooked, the Okinawan variety becomes creamy, making it excellent for mashing.

You can distinguish them by their skin color. The Okinawan sweet potato has beige or off-white skin, while the Stokes Purple® has purple-tinted skin.

No, ube is a purple yam, a different species from the sweet potato. While both are purple, ube has a rough, bark-like skin, a thicker texture, and a different flavor profile, often described as having vanilla notes.

All purple-fleshed sweet potatoes are healthy, containing high levels of anthocyanins and other nutrients like Vitamin C and fiber. The Okinawan sweet potato is particularly noted for its role in the traditional Okinawan diet, associated with longevity.

Due to their dry and starchy texture, Okinawan sweet potatoes are best prepared by steaming, boiling, or baking, which helps them become creamy. They are excellent for mashing, frying, and using in desserts.

Stokes Purple® sweet potatoes are typically more widely available in the mainland U.S. at major grocery stores. Okinawan sweet potatoes might be found in specialty health food stores or Asian markets. They can also be purchased online.