Walnut

Walnuts have been cultivated in Korea since they were introduced from China during the Goryeo Dynasty (918-1392), and the city of Cheonan became so renowned for its walnut confection (hodu-gwaja) that it remains the city's signature food to this day. The Donguibogam classifies walnut as warm in nature and sweet in flavor, noting it tonifies the kidneys, strengthens the brain, and moistens the lungs. Korean traditional medicine valued walnut's brain-like shape as a signature from nature indicating its ability to nourish the brain — a concept shared across many ancient medical traditions. In Korean cuisine, walnuts appear in ceremonial rice cakes, temple food desserts, and as a garnish for festive dishes, prized for their rich, buttery crunch.