Click here for more articles by Kormedi.com. Young adults in their 20s and 30s are lining up outside a specialty eatery in the Mangwon neighborhood of western Seoul, turning "cup mukbap" — a portable cup of acorn jelly served with rice and broth — into a viral street-food sensation. Even on weekdays, crowds gather well before doors open as people line up to grab a cup. The trend marks a generational shift for "dotorimuk," or acorn jelly. Long associated with traditional Korean side dishes and rustic tavern meals shared after mountain hikes, the staple is winning over younger diners who are embracing it as a modern wellness food. Every fall marks the harvest season when acorns turn brown and fall from oak trees. Raw acorns contain astringent tannins that produce a bitter taste, requiring cooks to soak the nuts repeatedly in water to leach out the bitterness before making jelly. Cooks then finely grind the acorns and let the sediment settle to extract pure starch, which they dissolve in water, boil and allow to cool into a thick jelly. This process removes most of the tannins, yielding