Dalgona or ppopgi is a Korean candy made with melted sugar and baking soda. It was a popular street snack in the 1970s and 1980s, and is still eaten as a retro food. When a pinch of baking soda is mixed into melted sugar, the thermal decomposition of the baking soda releases carbon dioxide, which makes the liquidized sugar puff up, and it becomes a light and crunchy candy once cooled and hardened. Typically, the creamy beige liquid is poured on a flat surface, pressed flat, and stamped with a patterned mold. Eaters try to trim their way around the outline or picture on the snack without breaking the picture. Traditionally, if this trimming is completed without breaking the candy, the consumer receives another free dalgona.
Modern cafes in Korea serve novel dalgona coffee beverages where dalgona-flavoured coffee cream is heaped on top of iced tea or coffee, as well as pastries such as scones. Some cafes also used dalgona to launch desserts such as bingsu and souffle.
Dalgona appeared in an episode of the Netflix series Squid Game, with a deadly version of the dalgona challenge being the second game played in the series. The success of the series led to a revival of the candy's popularity in South Korea and around the world, and sales doubled for street vendors. People have also taken to social media to make their own candy at home as a challenge.