''Zongzi'' is traditionally eaten during the Dragon Boat Festival which falls on the fifth day of the fifth month of the Chinese calendar , commemorating the death of Qu Yuan, a famous Chinese poet from the kingdom of who lived during the Warring States period. Known for his patriotism, Qu Yuan tried unsuccessfully to warn his king and countrymen against the expansionism of their Qin neighbors. When the Qin Dynasty general Bai Qi took Yingdu, the Chu capital, in 278 BC, Qu Yuan's grief was so intense that he drowned himself in the Miluo river after penning the Lament for Ying. According to legend, packets of rice were thrown into the river to prevent fish from eating the poet's body. Another version states that zongzi were given to placate a that lived in the river.
The shape of ''zongzi'' range from relatively tetrahedral to cylindrical. Wrapping a ''zongzi'' neatly is a skill which is passed down through , as are the recipes. Like ''tamale''-making in Mexico, ''zongzi''-making was traditionally a family event with everyone helping out, but that is less common now.
While traditional Chinese ''zongzi'' are wrapped in bamboo leaves, the leaves of , maize, banana, , or leaves are sometimes used as substitutes in other cultures. Each kind of leaf imparts its own unique smell and flavour to the rice.
The fillings used for ''zongzi'' vary from region to region, but the rice used is always glutinous rice . Depending on the region, the rice may be lightly precooked by stir-frying or soaked before using. Fillings may be sweet, with:
*Skinless mung beans
*Red bean paste
Or savoury with fillings such as:
*Chinese black mushrooms
*Salted duck eggs
Red bean paste ''zongzi'' take a particularly long time to prepare. The used for the filling must be simmered until soft, drained, skinned, and mashed into a paste that is stir-fried with sugar.
''Zongzi'' need to be or for several hours depending on how the rice is treated prior to filling. Once cooked, the ''zongzi'' can easily be frozen for later consumption. Frozen ''zongzi'' are available for sale in many Chinese markets.
*''Pseudo-zongzi'' : Instead of glutinous rice, mochi-like balls of glutinous rice flour are used to "contain" the filling of the ''zong''. These ''zong'' are typically smaller than most ''zongzi'' and much more sticky. This is how the Hakka traditionally make their zongzi .
*''Jianshui zong'' : The glutinous rice is treated with lye water , which gives them a distinctive yellow colour. ''Jianshui zong'' are typically filled with sweet fillings, although some are unfilled. This is the variation that usually contain no filling and are often eaten with sugar or light syrup.
*''Nonya zong'' : A specialty of Peranakan cuisine. The ''zong'' are made in similar style with similar fillings as Southern ''zong'', however the wrapping used are pandan leaves.
*Due to their prolonged cooking times, doneness is a constant issue with cooking zong. An old superstition says that it will not cook properly if a pregnant woman enters the kitchen while they are being steamed.
*In 2005, the earliest zongzi ever found in China was discovered in a 700 year old tomb in Dean County, Jiangxi Province.
*Chinese authorities issued ''zongzi'' health warnings for the 2006 Dragon Boat Festival due to copper s being used to enhance the color of the leaves used for wrapping in some factories.