Salt cod is cod that has been filleted, layered in coarse salt, and allowed to dry, a preservation method that sustained Atlantic communities for centuries. The salt draws out moisture so thoroughly that the fish keeps for months without refrigeration, and drying concentrates its flavour into something intensely savoury. Before cooking it must be soaked for a day or more, with several changes of water, to remove the excess salt and rehydrate the flesh. It is a cornerstone ingredient across southern Europe and the Caribbean: bacalao in Spain, bacalhau in Portugal, and saltfish with ackee in Jamaica. As a cheap, durable source of fish protein it fed sailors, slaves, and peasants, and it remains beloved for its unique texture and depth.