The Ultimate 2-Minute Microwave Secret to Perfect Crunchy Korean Candied Sweet Potatoes

When the weather cools down or you are simply craving a delightful afternoon snack, there is nothing quite like Goguma Mattang. This traditional Korean sweet treat features deep-fried chunks of sweet potatoes coated in a beautifully glossy, caramelized sugar syrup. It is a staple street food and a nostalgic childhood snack in Korea that brings immense joy to people of all ages. However, making it at home can sometimes be tricky—people often worry about the sweet potatoes not cooking thoroughly on the inside or the syrup turning into hard candy. In this comprehensive guide, we will walk you through a foolproof recipe with a brilliant microwave hack that guarantees an irresistibly crunchy exterior and a soft, fluffy interior every single time. Read on to master this fantastic recipe!

1. Essential Ingredients for the Perfect Snack

Creating this magical dessert requires only a handful of pantry staples. Here is what you need to prepare:

  • Main Ingredients: 4 medium-sized sweet potatoes, enough cooking oil for frying.
  • For the Caramel Syrup: 3 tablespoons of sugar, 2 tablespoons of oligosaccharide (or light corn syrup), 2 tablespoons of water, a pinch of salt, and 1 tablespoon of black sesame seeds.

[Ingredient Tips & Substitutions]

Sweet Potatoes: Asian sweet potatoes with reddish-purple skin and pale yellow flesh yield the best texture. Chestnut sweet potatoes offer a fluffy bite, while honey sweet potatoes provide an incredibly moist and sweet experience. Cooking Oil: Use a neutral oil with a high smoke point, like canola, sunflower, or grapeseed oil. Syrup Alternatives: The pinch of salt is a secret ingredient; it dramatically enhances the sweetness and depth of the caramel through a contrast effect.

2. Prepping the Sweet Potatoes Like a Pro

Proper preparation is the foundation of achieving that perfect texture.

  1. Washing and Peeling: Wash the sweet potatoes thoroughly. Using a vegetable peeler, partially peel the skin. Leaving some skin on provides a rustic, appealing look and adds nutritional value.
  2. Cutting to Size: Cut them into bite-sized chunks. Consistency in size is crucial so they all cook evenly in the hot oil. If they are uneven, some pieces might burn before others are fully cooked.
  3. Removing the Starch: Submerge the cut pieces in a bowl of cold water for about 10 minutes. This step draws out excess surface starch, preventing the pieces from sticking together and ensuring a crispier crust when fried.

3. The Microwave Hack for Saving Time

Deep-frying raw sweet potatoes until they are fully cooked inside can take a long time and risks burning the outside. Here is our secret time-saving trick:

  • Microwave Pre-cooking: After draining the sweet potatoes from the cold water, place them in a microwave-safe dish and microwave for about 2 to 3 minutes. This partially cooks the inside, dramatically reducing the frying time. It guarantees a soft, fully cooked interior.
  • Drying is Essential: When they come out of the microwave, they will be steamy and wet. Use paper towels to pat them completely dry. Frying wet food causes the hot oil to splatter dangerously, so do not skip this safety step.

4. Achieving the Perfect Golden Fry

Now it is time to achieve that golden, crispy exterior.

  1. Heating the Oil: Pour cooking oil into a wok or frying pan. Heat the oil over medium heat. To test the temperature, drop a tiny piece of sweet potato in; if it sinks slightly and floats back to the top surrounded by bubbles within 2-3 seconds, the oil is ready.
  2. Frying in Batches: Carefully add the sweet potato chunks to the hot oil. Avoid overcrowding the pan, as this lowers the oil temperature and leads to greasy, soggy results. Fry in batches if necessary.
  3. Checking for Doneness: Fry until the edges turn a beautiful golden brown. To test if the inside is cooked, pierce the thickest piece with a wooden skewer. If it slides in smoothly, they are completely done.
  4. Draining Excess Oil: Remove the fried chunks and place them on a wire rack or a plate lined with paper towels to drain any excess oil. This ensures your dessert is light and crispy, not heavy.

5. Making the Caramel Syrup (Do Not Stir!)

The syrup is what gives Mattang its signature glassy coating. Pay close attention here to avoid any mistakes.

  1. Combining Ingredients: In a wide skillet or pot, add the sugar, oligosaccharide, water, and that crucial pinch of salt.
  2. The Golden Rule: Turn the heat to medium-low and let the mixture melt and bubble on its own. Absolutely do not stir it with a spoon or spatula! Stirring will cause the sugar to crystallize, turning your glossy syrup into cloudy, hard clumps. If you need to mix it, gently swirl the pan by its handle.
  3. Waiting for the Bubbles: Once the sugar has completely dissolved and the mixture begins to bubble vigorously across the entire surface, it is perfectly ready for the sweet potatoes.

6. Coating and the Finishing Touch

  1. Quick Coating: Immediately add the fried sweet potatoes into the bubbling syrup. Turn off the heat or reduce it to the lowest setting.
  2. Tossing: Using two spatulas, quickly toss and flip the chunks so that every piece gets an even, glossy coat of the caramel syrup. Make sure every angle is covered for the best eating experience.
  3. The Final Garnish: While the residual heat is still present, sprinkle the black sesame seeds over the top and toss one last time. The black sesame seeds provide a gorgeous visual contrast and a delightful nutty pop with every single bite.

7. How to Serve and Store for Maximum Crispiness

  • Cooling for the Crunch: For the ultimate crispy candy shell, transfer the coated sweet potatoes onto a sheet of parchment paper, ensuring they are spaced apart so they do not stick together. Let them cool. As the sugar hardens, it creates a satisfying crackle.
  • Serving Suggestions: Goguma Mattang pairs incredibly well with a cold glass of milk, hot black tea, or an iced Americano. The slight bitterness of coffee or tea perfectly balances the sweet caramel.
  • Storage: These are best enjoyed immediately. If you have leftovers, store them in an airtight container at room temperature for up to a day. Refrigerating them will cause the syrup to melt and become sticky due to moisture.

Making Korean Candied Sweet Potatoes at home is a highly rewarding culinary experience. With these professional tips and tricks, particularly the microwave shortcut and the non-stirring syrup technique, you can easily create a flawless, café-quality dessert that your family and friends will absolutely adore. Enjoy the sweet, crunchy, and fluffy perfection!