Wood, rice, oil, salt, sauce, vinegar and tea are seven essential things in daily life, which are the so-called seven things to open the door. In the Song Dynasty, Wu recorded in Meng Lianglu Pu Jie: "What can't afford to build a home every day is rice, oil, salt, sauce and vinegar tea." In the Yuan Dynasty, Wuhan minister Yu wrote: "Seven things to get up in the morning, rice, oil, salt, sauce, vinegar and tea."
It is generally believed that the seven things of opening the door originated in the Song Dynasty. For people at that time, the seven things to open the door were a fresh food, because rice was the main food in the Song Dynasty, and the sauce in the Song Dynasty meant soy sauce. In addition, before the Song Dynasty, vinegar was not a necessity.
Many literati like to write the lyrics of seven things to open the door. It is reported that the arrangement and content of the seven events are very particular, and they are all related to the long-standing food culture in China.
When the proverb "Seven things to open the door" began, there were some controversies. However, with the improvement of living standards, the seven things of opening the door have also improved accordingly. In most parts of China, firewood has been replaced by liquefied petroleum gas and natural gas.