1. Buy back the big blue crab, wash it, remove the umbilicus, remove the claws, open the shell, remove the crop, remove the gills and leaves, cut into pieces, add a bottle and a half of rice wine (if you have a good amount of alcohol, it will be fishy if you lack it, and bitter if you have too much), add some ginger slices or shredded ginger and a spoonful of salt, and marinate together for about half an hour.
2. Rinse the raw materials after soaking in water, filter for three times, and cut into small pieces for later use.
3. Put clean water and fresh ground into the pot to boil.
4. put in a pot of delicious and nutritious rehmannia crab soup until the crab turns red, and then it can be freshly baked.