Is the system of pit flooding handed down from ancient laws?

You mean the instant noodles in the instant noodle news some time ago, right? Of course not.

The "pit" of the ancient method is either to dig a pit and lay a plastic film, or to "pickle by the ancient method".

Pickling in the pit is not to put the vegetables in the pit, but to put the "jar" in the pit, either half buried or completely buried. The main purpose is to "use the ground temperature to reduce the temperature difference, so that fungi can reproduce continuously and stably", which is also a common method in pickling and brewing.

There were only two main pickling utensils in ancient times: stone jars and pottery jars.

Stone jars used for pickling are generally sealed with wooden boards, dustpans and cloth.