Gancha Jiru

Gancha-jiru is a soup made by grinding whole river crabs, a species of mitten crab caught in Tottori's clear streams, into a broth. The crab's claws and legs are covered in fine hairs said to resemble seaweed debris, which is where its Japanese name comes from. Once the ground crab is strained and heated, the meat coagulates and floats up as light, fluffy curds, which carry the concentrated flavor of the crab.

The crab, with its shell removed, is blended with a measured amount of water until it turns into a smooth paste. This is strained through a sieve, combined with eggplant and water in a pot, and brought to a boil. Once boiling, soy sauce and sake are added, followed by chopped scallion just before the heat is turned off. The soup can also be seasoned with miso alone, and some households add mashed tofu. In the past, live river crabs were reportedly pounded to a pulp in a stone mortar with a wooden pestle instead of using a blender.

Mitten crabs are born in the sea, grow up in rivers, and return to the sea to spawn, and in Tottori they are said to have long gone by several local names — kawagani, egani, tsugani — as a familiar, everyday food. The soup is eaten from autumn into winter, when the crabs are in season, and females that have begun to carry roe are reported to be especially prized as a delicacy. Grinding the crab whole, meat and all, is thought to have become the standard way to make the most of a crab that otherwise yields relatively little flesh.