Goguma mattang is one of my favorite sweet Korean snacks. Deep-fried then shellacked in a syrup, sweet potato chunks take on impossibly crispy shells that shatter to reveal a soft, fluffy interior.
I’ll always remember the first time I tried goguma mattang. My grandma brought freshly made goguma mattang to me with some iced water and a fork. I thought the water was for drinking, but to my surprise, my grandma told me to dunk the sweet potatoes in it! I was skeptical—wouldn’t this make the potato soggy? But, the syrup coats the sweet potato in a way so that it creates a barrier between the cool water and the sweet potato. That memory—of biting into the crispy potato, cool on the outside, warm on the inside—is one that’s stuck with me all my life. (If you’re not totally sold, just be sure to let the caramelized sweet potatoes cool down for at least 10 minutes before eating, lest you scorch the roof of your mouth.)
Be sure to use Korean or Japanese sweet potatoes, those with a purplish skin and pale interior, as they are drier and slightly sweeter than their American counterparts. A less-moist interior means these fry up significantly crispier and fluffier, and the sweeter flavor stands up to the assertive glaze, whereas the more muted sweetness of a yam might get lost here.
I love sprinkling toasted black sesame seeds onto these just as the syrup is setting, because it adds such great savoriness, richness (and extra crunch). A sign of well-made goguma mattang: each piece should sound like ice cubes hitting a glass plate when spooned onto a serving platter. —Catherine Yoo
- Prep time 10 minutes
- Cook time 20 minutes
- Serves 4
Korean or Japanese sweet potatoes (about 2 medium)
plus 3 tablespoons canola oil, plus more as needed
roasted black sesame seeds (optional)
roasted, unsalted peanuts, roughly chopped (optional)
- Wash and peel the sweet potatoes. Cut the sweet potatoes into medium to large 1 ½-inch chunks. Make sure the chunks are similar in size so that all the pieces are able to cook evenly.
- In a medium pot, heat 4 cups of canola oil (or enough oil to cover the sweet potatoes) to 350°F.
- If you decide to garnish your candied sweet potatoes, you can re-toast your black sesame seeds and peanuts separately while waiting for the oil to come up to temperature. Toast the black sesame seeds in a small pan for about 1 minute, or until fragrant. Remove from heat and put aside in a small bowl. If using peanuts, lightly reheat the peanuts in the same pan for about 30 seconds, or until fragrant, and set aside.
- Once the oil reaches 350°F, deep-fry the sweet potatoes until golden brown for about 12 minutes. Make sure to occasionally stir the sweet potatoes since the ones on the bottom will brown faster than the ones on top. Once golden, place them on a tray lined with paper towels to absorb the excess oil.
- Make the syrup: In a large saucepan, place 3 tablespoons of the oil that you used to fry the sweet potatoes along with 8 tablespoons of granulated sugar on medium heat. Do not stir the sugar and leave it alone to let it melt. Stirring the sugar will crystalize the syrup.
- Set aside a tray lined with parchment paper. Once the sugar starts to brown after about 5 minutes, you can swirl the syrup around by moving the pan. Let the syrup fully brown after another 2 minutes.
- Once the syrup is browned, stir in the fried sweet potatoes and coat with the syrup. Be gentle so that they do not break apart. After they are coated, spread the sweet potatoes out evenly on a parchment lined tray and sprinkle with your choice of black sesame seeds, crushed peanuts, or both.
- You can eat them immediately by dunking a piece in ice water before eating or let it cool for 10 minutes before serving.