The jingle for Pixian Doubanjiang used the ancient fermentation method, "flip it over during daytime, expose it at night, sunbathe it in sunny days, cover it when it rains."

Pixian is located in the plains, with more sunshine, higher air humidity, and no water pollution.

Pixian doubanjiang is a geographical indication (GI) protected product, with its quality assessment standards last published in 2006, up to GB/T 20560-2006.

It states:[7] The optimal process conditions for Doubanjiang are 56% water, 10% added salt, 40°C fermentation temperature, and 40 hours of Qu starter-making time.

Normal home-made or factory-produced doubanjiang rarely has the long fermentation time that gives the Pixian version its character.

Therefore, storing them at room temperature after opening is likely to accelerate the growth of microorganisms and make the condiments go bad.