Candied Sweet Potatoes, known in Japan as Daigaku Imo, are a timeless snack that combines rich flavor with an irresistible texture. Each bite offers a crisp caramelized coating that contrasts beautifully with the naturally sweet and creamy flesh of Japanese sweet potatoes. The name “Daigaku Imo,” which translates to “university potatoes,” reflects their popularity among students in early 20th-century Tokyo, when they were sold inexpensively near campuses as a filling and satisfying snack. Over time, this humble treat grew into a nostalgic comfort food enjoyed during autumn and winter across Japan, often paired with a hot cup of green tea. Today, Daigaku Imo embodies both tradition and indulgence, serving as a dish that feels festive yet approachable, hearty yet delicate.

Full Recipe:

Ingredients

• Japanese sweet potatoes (Satsumaimo)

• Sugar

• Water

• Mirin (or extra sugar if preferred)

• Rice vinegar (unseasoned)

• Soy sauce

• Neutral frying oil (for deep-frying) or oil for shallow-frying

• Toasted black sesame seeds (for garnish)

Directions

• Wash and peel the Japanese sweet potatoes, then cut them into medium-sized wedges or rangiri slices for even cooking and extra surface area.

• Place the cut potatoes into a bowl of water for about 10 minutes to remove excess starch. Drain and pat dry thoroughly with a clean towel.

• Heat neutral frying oil in a deep pan or skillet to around 320 °F (160 °C). If shallow-frying, use just enough oil to cover half the potato pieces.

• Fry the sweet potato wedges in batches until they are golden on the outside and tender inside, about 5–7 minutes. Remove and drain on paper towels.

• In a separate pan, combine sugar, water, mirin, and a small splash of rice vinegar. Heat gently without stirring until the mixture turns into a smooth, glossy syrup. Add a tiny splash of soy sauce for depth.

• Quickly add the fried sweet potatoes to the hot syrup and toss until evenly coated in the shiny glaze.

• Transfer the glazed potatoes to a serving plate and immediately sprinkle with toasted black sesame seeds before the glaze hardens.

• Serve warm and enjoy with tea, as a snack, or as part of a meal.

Nutrients

• Calories: 306 kcal

• Carbohydrates: 43 g

• Protein: 2 g

• Fat: 14 g

• Saturated Fat: 11 g

• Sodium: 155 mg

• Potassium: 461 mg

• Fiber: 4 g

• Sugar: 22 g

• Vitamin A: 19,305 IU

• Vitamin C: 3 mg

• Calcium: 47 mg

• Iron: 1 mg

Why This Recipe Stands Out

This dish is not simply a version of candied sweet potatoes—it is a cultural icon that represents Japanese ingenuity in balancing flavors and textures. The crisp shell of caramelized sugar gives way to the soft interior of satsumaimo, producing a contrast that is deeply satisfying. What makes Daigaku Imo special is the glaze: it is not just sugar but a blend enhanced by mirin, soy sauce, and rice vinegar. These additions elevate the flavor with notes of umami and tang, ensuring the sweetness is never one-dimensional. Unlike many desserts, it offers flexibility in preparation, as it can be deep-fried for an authentic crunch or shallow-fried with steaming for a lighter approach. Its history as a university snack ties it to simplicity, affordability, and comfort, which is why it remains beloved across generations.

The Benefits of the Ingredients

Japanese sweet potatoes are the heart of this recipe, prized for their dense, creamy sweetness. Nutritionally, they are rich in vitamin A, which supports healthy vision and immunity, and they offer potassium and dietary fiber, both of which help regulate digestion and support heart health. The glaze’s components also contribute more than flavor alone. Rice vinegar prevents the sugar from crystallizing, giving the glaze its glassy smoothness while adding a subtle tang. Soy sauce introduces savory depth that balances the sugar’s intensity, while mirin contributes a mellow sweetness and shine. Even the garnish of toasted black sesame seeds is meaningful—they provide healthy fats, minerals like calcium and iron, and a nutty warmth that rounds out the dish. Altogether, these ingredients transform Daigaku Imo into something indulgent yet nourishing.

Cooking Tips

Success with Daigaku Imo depends on attention to detail during preparation. Cutting the sweet potatoes using the rangiri technique, where the vegetable is rotated slightly with each diagonal cut, maximizes the surface area and creates irregular edges that crisp more easily. When preparing the syrup, it is best to combine sugar and water off the heat so they dissolve evenly. Once heating begins, avoid stirring, as this may cause crystallization, and allow the syrup to cook until it achieves a glossy, amber sheen. The addition of rice vinegar stabilizes the syrup, ensuring a smooth coating. For deep-frying, maintaining a steady oil temperature around 320 °F (160 °C) is key so that the sweet potatoes cook through without burning. Those seeking a lighter option can steam the sweet potatoes before shallow-frying, which reduces oil absorption while still delivering the signature crisp exterior. It is also important to sprinkle sesame seeds onto the potatoes immediately after glazing so they stick before the syrup hardens.

Serving Suggestions

Daigaku Imo shines as a warm snack served fresh from the pan, accompanied by green tea to balance its sweetness. It can also be paired with savory spreads; for example, alongside roasted meats or on a charcuterie board, where the sweet crunch contrasts beautifully with salty, cured flavors. For a dessert presentation, it can be plated with vanilla ice cream or drizzled with condensed milk, creating a playful East-meets-West twist. At parties, serving the glazed potatoes on skewers makes them easier to enjoy as finger food while also adding charm to the presentation. Families often find that leftovers, when reheated gently in an oven, regain much of their crunch, allowing the dish to be enjoyed over several days. Whether served casually or as part of a festive meal, these candied sweet potatoes adapt to the occasion, always offering comfort and delight.

Conclusion

Daigaku Imo is a recipe that bridges history, flavor, and texture in a single dish. Its glossy caramel glaze and tender sweet potato base make it visually striking, while the blend of sugar, soy sauce, and vinegar ensures every bite is flavorful rather than overly sweet. Rooted in its origins as a filling and affordable student snack, it has grown into a seasonal treat cherished across Japan for its ability to warm both body and spirit. Beyond being a nostalgic autumn and winter favorite, it delivers impressive nutritional benefits, particularly its abundance of vitamin A and fiber. Whether fried in the traditional way or adapted with modern lighter methods, it remains a dish that embodies comfort and craftsmanship. In a world where recipes often come and go, Daigaku Imo endures as a reminder that the simplest ingredients, when prepared with care, can create something truly timeless.