Scrub the bound crabs with brush and water. Do not untie the straws!!!! (you do not want any escape artists running around your home) Set aside.
Prepare the Steamer: Half fill a wok with water and then put a small bowl on top and then a plate on top of this and prepare a lid to cover. (Or if you have a bamboo steamer you can use this- whatever you like or have access to.)
Put some dried perilla leaves and slices of ginger flat in the plate. Lay the freshwater hairy crabs on top of the plate BELLY SIDE UP and place the plate in the wok. (The reason for belly side up is that most of the meat is on the top of crab and this will be closest to the heat)
Steam the crabs according to size and the number of crabs in your steamer. Crab weighs less than about 7 oz cook for about 15 minutes. Crab weighs over 7 oz cook for approximately 18-20 minutes. If you have more crabs in your steamer you may have to increase the time. You will know the crabs are done when their color changes from a green/gray color to a nice orange crimson color.
Allow the crabs to rest for 10 minutes in the steamer just so they are cool enough to handle.
Prepare vinegar sauce: For each person combine a few tablespoons of Chinese black vinegar, brown sugar and minced ginger in a little bowl for dipping. (I usually never measure but more of a dash of this and a dash of that and taste test and adjust to your liking)
Prepare the Hua Mei (Plum Wine) - In a small sauce pan, place Hua Mei and a wedge of ginger and warm up. Do NOT boil. Place wine in tea cups or heat proof cups to serve.
Bring Shanghai hairy crabs to the dinner table. Untie the straws and served with a saucer of Chinese vinegar, sugar and minced ginger. Enjoy with a cup of warm Hua Mei. Let the feast begin.