Fresh gaotuan made at a workshop in Rugao. [Photo/ntfabu.com]

Early spring has always been a time when the people of Rugao in Nantong, East China's Jiangsu province, indulge in gaotuan, or sweet green glutinous rice balls.

Unlike qingtuan, also a popular spring snack in Jiangsu and Zhejiang provinces, gaotuan is made with sweet wormwood instead of Chinese mugwort.

The key to making delicious gaotuan is the sweet wormwood, which must be picked before the Qingming Festival, as that is when the leaves are the tenderest.

Gaotuan handmade and packaged at a workshop in Rugao. [Photo/ntfabu.com]

Boiled sweet wormwood is squeezed into juice to dye the glutinous rice flour green. The snack is traditionally stuffed with red bean and sesame.

The snack used to be offered to ancestors during the ancestor worship ceremony on the Qingming Festival. Nowadays, it has become a popular spring delicacy and has various other fillings, including purple sweet potato, yolk, bamboo shoot cubes, and dried meat floss.

Gaotuan is best eaten at room temperature after being steamed, which brings out the flavor of the rice balls.