Chestnut, Pumpkin or Honey: Reading a Korean Sweet Potato

Watch a Korean shopper at a fruit-and-vegetable stand in late October and you'll notice they don't ask for a variety name. They ask about texture. Korean sweet potatoes, goguma, are sorted at the counter by how they eat once cooked, and learning the three or four labels is the quickest way to get the one you actually want.

Bam goguma, the chestnut type, has pale yellow flesh that roasts dry and crumbly, with a nutty smell close to a roasted chestnut. It is filling and slightly floury, which is why Koreans like it with something to drink. Hobak goguma, the pumpkin type, is the opposite: deep orange flesh that turns soft, wet and almost custard-like in the oven. In a taste comparison of ten varieties, the Rural Development Administration described chestnut-colored types as strong in chestnut aroma and the orange types as moist, with notes of squash and carrot.

Honey goguma (kkul goguma) is the label you'll see most on signs and delivery boxes. It is a market name rather than one official variety. Sellers use it for potatoes that turn sticky and syrupy when roasted, often ones that have been stored for a while after harvest, because sweet potatoes keep converting starch into sugar in storage. That is also why a goguma bought in December usually tastes sweeter than one bought in September. Then there is jasaek goguma, the purple-fleshed type, milder in sweetness and the one behind most violet lattes and breads.

The season follows the harvest. New-crop potatoes start arriving from late summer, and stored potatoes take over through the colder months, so the stretch from now until early spring is when you'll see goguma everywhere: in boxes at markets, in roasters by the counter and on cafe chalkboards.

The Convenience-Store Roaster and How to Buy One

The scent usually reaches you before you see it. Near the counter or just inside the door of many Korean convenience stores, a small glass-front oven holds a bed of hot stones with a row of sweet potatoes resting on top. The stones hold heat evenly, so the potatoes roast slowly in dry heat instead of steaming, and the skin pulls away from caramelized flesh at the ends. Staff load a batch, leave it to roast and keep the finished ones warm in the case, which is why a convenience-store goguma is ready the moment you walk in.

Buying one is simple. Look through the glass, point to the size you want or simply say "goguma," and a staff member will lift it out with tongs into a paper sleeve. You pay at the same counter like any other item. If the case is empty, a new batch may be on its way; asking "Goguma isseoyo?" (Is there sweet potato?) will get you an answer. Not every branch has a roaster, so if the first store on the corner doesn't, the next one often will. Our guide to Korean convenience store food covers what else to pick up while you are there; a cold carton of milk is the classic partner.

The chains treat goguma as a serious seasonal product. 7-Eleven started selling roasted sweet potatoes on September 14 this year and, according to the company, uses the moist, deep-orange Hopungmi variety through November before switching in December to Beniharuka potatoes that have been aged for about three months for extra sweetness. The chain kept its price at 2,200 won while raising the minimum weight per potato. GS25 began its winter snack lineup, roasted sweet potatoes included, at about 5,000 stores on October 1, and CU also runs roasters in many of its branches.

Goguma Lattes and the Cafe Dessert Case

A goguma latte is sweet potato, not coffee. Korean cafes blend roasted or steamed sweet potato paste with milk, so the drink is thick, gently sweet and usually caffeine-free. It has been on menus at Korean cafe chains for years, which makes it an easy order on a cold afternoon when you have already had your coffee. Hot is the classic way to drink it, though iced versions are common too, and many cafes finish it with a dusting of crumbs or nuts.

This autumn brought new takes. Starbucks Korea launched the Castella Sweet Potato Latte on September 15, made with a sauce of roasted sweet potatoes from Muan in South Jeolla Province, mixed with milk and topped with castella cake crumbs and chewy pearls. It is caffeine-free and sits on the autumn menu next to chestnut desserts such as a Mont Blanc cheesecake. Seasonal drinks rotate, so check the Starbucks Korea app before you go. Coffee chain The Venti added a Yeongam Sweet Potato Latte on October 23, made with sweet potatoes from growers in Yeongam County and sold hot or iced for 3,900 won at its stores nationwide.

The dessert case follows the same mood. Bakeries bring out goguma cake, layered with mashed sweet potato instead of buttercream, and soft rolls shaped and dusted to look like a small roasted sweet potato. If you prefer something less sweet, ask for your latte "deol dalge," which means less sweet; many cafes will adjust the syrup.

The Winter Street Cart and Its Drum-Can Oven

The convenience store is reliable, but the street cart is the version people remember. Once the evenings turn properly cold, a few vendors set up near subway exits, markets and residential corners with a converted steel drum: a fire burns underneath, and the potatoes roast in small drawers cut into the side. They are sold by the paper bag, too hot to hold at first, with skins blackened in places and the flesh inside soft and smoky.

These carts are fewer than they once were, so spotting one is part of the fun. They often share a corner with roasted chestnut sellers and the fish-shaped pastries in our bungeoppang guide, and they tend to work from late afternoon into the evening. A bag usually costs a few thousand won, and prices vary by size and neighborhood. Carry small bills: many carts take cash, and some take bank transfers, but cards are not a given. If you are planning a full evening of snacking, our guide to winter street food in Seoul maps out the rest of the menu.

Eat it the local way: peel back the skin with your fingers and eat it while it steams. At home, Koreans often pair goguma with kimchi, especially cold radish kimchi or dongchimi broth, and the salty, sour crunch against the soft sweetness is worth trying at least once.