How long does it take to steam hairy crabs? It depends on the heat and the number of crabs. Generally, families eat less than 10. Steam hairy crabs in cold water for about 20 minutes. You can choose one to open the crab shell. If the crab paste is solidified and caked, it should be almost the same. Of course, it is best to steam more, and try to cook it thoroughly before eating, such as steaming for about 25 minutes (maybe the meat is a little old); ~