15 minutes.

It takes 15 to 20 minutes to boil crabs, which can ensure the maturity of the crabs and make the crabs taste more delicious. You need to choose the cooking time reasonably according to the size of the crab. When cooking crabs, it is best to use cold water in the pot to ensure that the crabs are evenly mature. Crabs are cold, so you can eat them with ginger vinegar sauce and rice wine, but don't eat too much.

You must know that crab is a delicacy in food. There is a folk saying that "a plate of crabs is the top dish on the table". It is not only delicious, but also rich in nutrients. It is a high-protein supplement. According to the place of origin, it can be divided into three types: river crab, river crab and lake crab. River crabs from Hebei and Tianjin are the most famous, river crabs from Nanjing are the best, and lake crabs from Yangcheng Lake in Kunshan, Jiangsu, Weishan Lake in Shandong, and Gaochun Gucheng Lake in Nanjing are of better quality.