Banh chung is made of sticky rice, pork and green beans, with every ingredient wrapped in large green leaves called la dong (Phrynium placentarium leaf). Making banh chung requires care and precision at every step. Rice and green beans are soaked in water for a day, while pork is usually mixed with pepper for several hours before being wrapped. Squaring off and tying the cake with bamboo strings require skillful hands to make a perfect square.

Banh chung was invented by Prince Lang Lieu, the 18th son of the Hung Emperor, as an offering to the king’s ancestors during Tet. According to legend, 3,000-4,000 years ago, the Prince made round and square cakes, the round cake symbolizing the sky and the square banh chung or chung cake symbolizing the earth, which in ancient times was believed to be square.

Since the cakes he offered were of special meaning and delicious taste, Lang Lieu was selected to be the next emperor by his father. Since then, banh chung have been placed on every Vietnamese family’s altar to worship ancestors.

The preparation of chung cake provides an opportunity for family members to come together, sitting around the warm fire, recount stories of the past and exchange wishes for health and prosperity. In big cities, although the habit of extensive cake preparations has died out with the shift to urban life and busy lifestyles, ancestor worship and cake offerings persist, evidence of the Vietnamese loyalty and deep gratitude to their ancestors.