Lake Tai and the hairy crab of Yangcheng

Lake Tai (Taihu) lies in the Yangtze delta between Suzhou, Wuxi and the Zhejiang border, one of the great freshwater lakes of the lower Yangtze and the centre of the water country that Fuchsia Dunlop describes in Land of Fish and Rice. Yangcheng Lake, a smaller lake to the north-east near Suzhou, gives its name to the Yangcheng Lake hairy crab, the Chinese mitten crab Eriocheir sinensis, whose name is registered as a Chinese Geographical Indication.

The country around Lake Tai is a land of lakes, canals and paddies, and its cooking begins with what the water yields: fish, shrimps, crabs, water shoots, lotus roots, water chestnuts and the rice of the surrounding fields. Dunlop treats the lower Yangtze as the land of fish and rice in the literal sense, a cooking whose first principle is the freshness of the ingredient and whose seasoning is generally light, so that the sweetness of the flesh is left to speak. Lake Tai is associated with a group of small freshwater fish and shrimps, among them the whitebait, the whitefish and the river shrimp, which are cooked simply by quick frying, steaming or poaching. The Chinese mitten crab is a catadromous animal. It lives and grows in fresh water, and the adults travel downstream towards the estuary in autumn to breed in brackish water. The autumn migration is the season of the crab at table, and the weeks after the ninth lunar month are those when the females are prized for their roe and the males, a little later, for the rich paste of their reproductive glands. The animal is distinguished by the dense hair on its claws, which gives the common English and Chinese name, dazhaxie, hairy crab. The Yangcheng Lake crab holds the reputation among the crabs of the region, and the registered Geographical Indication reflects the standing of the lake's name in the markets of Shanghai, Suzhou and beyond. Because the name carries such value, the crabs from the lake are conventionally sold with a mark of origin, and the existence of a registered name is a matter of record rather than of taste. Dunlop notes in her account of the lower Yangtze that the crab season is one of the great gastronomic moments of the Jiangnan year. The approved way of cooking a hairy crab is to steam it whole, usually tied to keep the claws from loosening, and to serve it with a dip of Zhenjiang vinegar with shreds of fresh ginger. The diner takes the crab apart by hand, working through the shell, the roe, the claws and the legs, and the meal proceeds slowly, with the dissected shell as its record. Beyond the steamed crab, the region makes dishes in which the crab's roe and meat are cooked into other preparations, such as crab-roe tofu and crab-meat dumplings, using the picked meat of the animal as a seasoning as well as an ingredient.

The hairy crab is eaten in autumn and the Chinese dietary tradition counts the crab a cooling food, which is why it is served with ginger and with warmed huangjiu or ginger tea, a pairing the tradition holds to balance it. The usual table is a family or friends' meal built around the crab, with Zhenjiang vinegar, ginger shreds and a small number of plain dishes beside it so that the sweetness of the roe and flesh is not overwhelmed.