Thirty minutes. Generally speaking, all the normal head of hairy crabs only need to steam thirty minutes or so, to boil the water to take possession of ten minutes, after the water boiled also need to steam fifteen minutes to twenty minutes or so. But there are exceptions, if the hairy crab is very big words, then need to steam a little longer, but it is recommended to control as much as possible within an hour, in order to prevent the steam time is too long and give the taste impact. Thirty minutes. Generally speaking, all normal block head hairy crabs only need to steam thirty minutes up and down, to boil the water to take possession of ten minutes, after the water boiled also need to steam fifteen minutes to twenty minutes up and down. But there are exceptions, if the hairy crab is very big words, then you need to steam a little longer, but it is recommended to control as much as possible in an hour, in order to prevent the steam time is too long and to the taste of the impact. 1, rice cooker cooking crab about 15 minutes to 20 minutes or so, the general hairy crab color change color, it means that hairy crabs are ripe. However, if you encounter a particularly large individual crab, you need to increase the time as appropriate. 2, when cooking crabs must be used in cool water in the pot, so that the crab legs are not easy to fall off, cooking out of the crab is more attractive. Must remember to cover the lid, so that the crab inside the cooked crab yolk will be more soft and sticky taste, more will not appear the phenomenon of scattered yellow. 3, the water after steaming 15-20 minutes can be, when the meat is tender and more nutritious, a short period of time to cook cooked, a long time the crab meat old taste is not good.