1. In summer when the temperature is high, frozen glutinous rice balls can be directly stored at room temperature for 6 hours. After 6 hours, the dumplings may smell, become soft and shapeless. When the temperature is low in winter, the reproduction speed of bacteria is slow, and it can last about 12 hours at room temperature.

2. Tangyuan originated in Song Dynasty. It was also a novel food that rose in Mingzhou (now Ningbo City, Zhejiang Province) at that time, that is, black sesame seeds and pork suet were used as stuffing, a little sugar was added, and glutinous rice flour was rubbed outside to form a circle. When cooked, it tastes sweet, soft and delicious, with endless aftertaste. At the same time, glutinous rice balls symbolize family reunion, and eating glutinous rice balls also means family happiness and reunion in the New Year, so it is a must-have food for the Lantern Festival on the fifteenth day of the first month.