If it is pure natural bracken, it is usually naturally dried during processing, so it is inevitable that there will be some dust or small impurities. Before soaking, it must be rinsed twice with warm water.
If it is prepared for frying, it is best to soak it in water of about 5 degrees, so that the bracken can be fully soaked. In the meantime, if it is cooled, it is recommended to change the water again. When people in Enshi, Hubei Province generally want to eat, they usually soak it in hot water on the first night, and eat it at noon or afternoon the next day. Otherwise, the dried vegetables will not swell well.
If it is stew or soup, just clean it with warm water and cut it into small pieces and put it into the pot for processing. Pteridium aquilinum will absorb a small amount of water when it swells, so put a little more water when cooking.