According to the industry encyclopedia, dried Nostoc flagelliforme needs to be soaked for about 2 hours to remove impurities, washed and gently rubbed after soaking to make its surface completely loose, and then washed and cooked with clear water. Dried Nostoc flagelliforme is a kind of seaweed. It is black in color and feels a bit like hair, so it is named Nostoc flagelliforme. Nostoc flagelliforme is soaked to make it absorb water and taste better.

Nostoc flagelliforme is actually a common algae plant, which grows in the desert plant list below. It is messy, dark in color, nutritious and edible. Many people call it "ground wool", which is rich in protein, calcium, iron and other substances and is very beneficial to human growth.