Boil ginger in water for five minutes, turn off the heat, cool slightly, pour in salt, stir until the salt dissolves, and when the water is still warm, add some fennel and pepper. When the water is completely cold, buy fresh choking crabs and make sure they are alive. Unscrew them with big feet, brush them first and put them in the treated salt water. Then scrub the whole surface of the crabs, drain them and immerse them in the treated water, which must be submerged. Pour a certain amount of white wine into the water, depending on your personal preference, and don't be afraid to pour more alcohol. Soak for 24 hours and you can eat it. When eating, take it out and drain it, then open it and eat it. Pour out the used water and do it next time. Then make salt water.