Korean Roasted Sweet Potato (Gungoguma): Winter Guide
The two-dollar snack that tells you winter has really arrived in Korea.
Short answer: Gungoguma is a whole sweet potato roasted with its skin on, traditionally in a drum can, until it is chewy outside and creamy inside. In downtown Seoul it costs about KRW 2,000-3,000 a piece (Korea.net), and you can also find it in convenience stores and department stores. Vendors sell it from late autumn through winter.
If you have ever walked through Seoul on a cold evening and followed a sweet, smoky smell to a tiny kiosk, you have met gungoguma. It looks almost too plain to write about: a sweet potato, cooked until the sugars caramelize and ooze through the skin. Yet ask a Korean what winter tastes like and this is one of the first answers. Here is how to find a good one, which type to pick, and how to make it at home.
What Is Gungoguma, and Why Do Koreans Love It?
The name breaks down simply: gun means roasted and goguma means sweet potato. Korea.net describes it as one of the nation's most popular winter street snacks, eaten hot, often with people blowing on it before the first bite. Wikipedia adds that it is traditionally roasted in drum cans and is popular in both North and South Korea.
The street-cart version has become rarer. Korea.net notes that kiosks with the special drum canister have greatly declined in number in recent years, which is partly why convenience stores and department stores now sell it too. Personal Take: that shift is the real story. The snack is not disappearing; it is moving from the corner of the street to the heated counter next to the register.
Which Korean Sweet Potato Is Best for Roasting?
This is where most English articles stop at "sweet potato," and where a little knowledge goes a long way. Korea Bridge lists three common types, and Wikipedia notes which suits roasting best.
Sources: Korea Bridge, "Korea's Love Affair with Sweet Potatoes"; Wikipedia, "Roasted sweet potato."
A third voice, The Takeout, describes the purple-skinned Korean variety sold in the US as having off-white or slightly yellow flesh and a chestnut-like flavor that is a bit drier than orange sweet potatoes. So if one stall's potato tastes drier and nuttier than another's, you are likely comparing a bam type with a hobak type, not a good cook with a bad one.
How to Eat Gungoguma Like a Local
Korea.net recommends the pairing locals swear by: gungoguma with fermented, cold, crunchy side dishes such as dongchimi (water radish kimchi), baechu (cabbage) kimchi and nabak kimchi. The sweet, soft potato against a sour, icy broth is the point. Field Note: if a vendor hands it to you wrapped in newspaper or paper, as Korea Bridge's author remembers, peel the skin back from the top only. It keeps the heat in and the sticky syrup off your gloves.
Where to Buy Roasted Sweet Potato in Korea
- Street kiosks: Fewer than before, but still the best smell. Prices in downtown Seoul run about KRW 2,000-3,000 per piece (Korea.net), and they vary by region.
- Convenience stores and department stores: Reliable and warm. Ask staff for "gun-goguma" and point at the heated case.
- Frozen or dried versions: Wikipedia notes sweet potatoes are dried into gun-goguma-mallaengi, a half-dried chewy snack, or frozen into ice-gun-goguma. The dried kind travels well as a souvenir.
One more twist: gungoguma ice cream and smoothies are now enjoyed in summer too, according to Wikipedia, so the snack is no longer strictly seasonal.
How to Make Gungoguma at Home (Oven Method)
You will not get drum-can smoke in a home oven, but you can get close. The Takeout suggests roasting Korean sweet potatoes at 400 degrees Fahrenheit (about 200 degrees Celsius) for roughly an hour, until a knife slides easily through the center.
- Scrub the potatoes and poke several holes with a fork. Choose a soft, moist type if you can find it.
- Roast on a lined tray at 400 F for about an hour, flipping once if you like.
- Test with a knife. It should slide through with no resistance.
- Let it cool until you can handle it, then peel the skin back in strips.
- Serve plain, with a cold radish kimchi on the side, as Korean cooks do.
In the US, The Takeout says you will mostly find Korean sweet potatoes at Asian markets, and notes an H Mart with a heated display case. I could not verify national availability beyond that, so check your local Korean grocer.
Common mistakes
Pulling the potato too early is the big one. Under-roasted, it is fibrous instead of creamy. The second mistake is buying a floury bam type when you want a sticky, dripping center; ask for a moist type, or just look for the darker, thinner ones.
Other Korean Winter Snacks to Pair It With
Gungoguma sits in the same family as roasted chestnuts, fish-shaped bread and egg bread. Our guide to roasted chestnuts (gunbam) is the closest cousin, while bungeoppang and gyeran-bbang will round out a cold-weather snack crawl.
Key Takeaways
- What it is: Skin-on roasted sweet potato, traditionally cooked in a drum can and sold hot from late autumn through winter.
- What to buy: About KRW 2,000-3,000 in downtown Seoul; pick a moist type for the creamiest result.
- How to enjoy: Pair it with a cold radish or cabbage kimchi, and look in convenience stores if you cannot find a kiosk.
Frequently Asked Questions
Your Turn
Do you prefer a sticky, syrupy gungoguma or a dry, chestnut-style one? Tell me in the comments where you tried it, and I will point you toward the closest cousin snack.
Explore More on the Blog
- Korean roasted chestnuts (gunbam)
- Bungeoppang, the Korean fish-shaped bread
- Why Korean egg bread is a winter classic
- Hotteok, the Korean street pancake
- Sujeonggwa, Korean cinnamon persimmon punch
Sources: Korea.net, Food and Travel feature on gungoguma; Wikipedia, "Roasted sweet potato"; Korea Bridge, "Korea's Love Affair with Sweet Potatoes"; The Takeout, "Korean Sweet Potatoes Are In A League Of Their Own"; Korea Herald recipe (Sept 17, 2026). Prices are snapshots and vary.