Historically, a number of different names were used to refer to the ''tangyuan''. During the of the Ming Dynasty, the name was officially settled as ''yuanxiao'', a name derived from the ''Yuanxiao festival'', also known as the Lantern Festival. This name literally means "first evening", being the first full moon after Chinese New Year, which is always a new moon. This name prevails in northern China.
In southern China, however, the prevailing names are ''tangyuan'' or ''tangtuan''. Legend has it that during Yuan Shikai's rule , Yuan disliked the name ''Yuanxiao'' because it sounded identical to "remove Yuan" , and so mandated that the name ''Tangyuan'' be used instead. This name literally means "round balls in soup". ''Tangtuan'' similarly means " in soup".
In both filled and unfilled ''tangyuan'', the main ingredient is glutinous rice flour. For filled ''tangyuan'', the filling can be either sweet or savoury.
Sweet fillings can be:
* Sesame paste - the most common filling;
* Red bean paste;
* Chopped peanuts and sugar. Celebrated on the longest night of the year, Dong Zhi is the day when sunshine is weakest and daylight shortest. The coming of winter is celebrated by families and is traditionally the time when farmers and fishermen gather food in preparation for the coming cold season. It is also a time for family reunions.
This celebration can be traced to the Chinese belief in yin and yang, which represent balance and harmony in life. It is believed that the yin qualities of darkness and cold are at their most powerful at this time, but it is also the turning point, giving way to the light and warmth of yang. For this reason, the Dong Zhi Festival is a time for optimism.
Dong Zhi is celebrated in style. The longest night of the year is a time to put on brand new clothes, visit family with gifts and to laugh and drink deep into the long nig
Savoury filling is usually a pork meat ball.
''Tangyuan'' is cooked in boiling water. Filled ''tangyuan'' is served along with the water in which it is boiled .
Unfilled ''tangyuan'' is served as part of a sweet dessert soup . Common types include:
* Red bean soup
* Black sesame soup
* Ginger and rock sugar;
* Fermented glutinous rice , Sweet Osmanthus and rock sugar.
The most famous varieties come from Ningbo and Wenzhou in Zhejiang Province. However, they are traditionally eaten throughout China.
Originally, ''tangyuan'' was associated with the Lantern Festival. However, it has also come to be associated with the and Chinese New Year in various regions. Today, the food is eaten all year round. Mass-produced ''tangyuan'' is commonly found in the frozen food section of Asian supermarkets in China and overseas.
In southern Vietnam, a similar dish, called ''chè x?i n??c'', is served in a mild, sweet liquid flavored with grated ginger root. In northern Vietnam, ''bánh tr?i'' and ''bánh chay'' are also very similar, with the latter being served with coconut milk. ''Gulab jamun'' is an Indian dessert that is made of fried dairy dough balls served in a bowl of syrup.