The nuts are soaked in water for 24 hours, and then boiled for 20 minutes or longer until fully expanded. Some anglers then leave the boiled nuts to ferment for 24–48 hours, which can enhance their effectiveness. If the nuts are not properly prepared, they can be toxic to carp. This was originally thought to have been the cause of death of Benson, a large, well-known female carp weighing found floating dead in a fishing lake, with a bag of unprepared tiger nuts lying nearby, empty, on the bank. An examination of the fish by a taxidermist concluded tiger nut poisoning was not the cause of death, but rather the fish had died naturally. History It has been suggested that the extinct hominin Paranthropus boisei (the "Nutcracker Man") subsisted on tiger nuts. C. esculentus was one of the oldest cultivated plants in prehistoric and Ancient Egypt, where it was an important food. Roots of wild chufa have been found at Wadi Kubbaniya, north of Aswan, dating to around 16,000 BC. Dry tubers also appear later in tombs of the Predynastic period, around 3000 BC. During that time, C. esculentus tubers were consumed either boiled in beer, roasted, or as sweets made of ground tubers with honey. The tubers were also used medicinally, taken orally, as an ointment, or as an enema, and used in fumigants to sweeten the smell of homes or clothing. Chufa continued to be an important source of food in the Dynastic period, and cultivation of the plant remained exclusively in Egypt. The tomb of the vizier Rekhmire from the 15th century BCE, shows peasants preparing and measuring tiger nuts to make votive cakes as offerings to the god Amun. The modern name for tiger nuts in Egypt is حب العزيز (Hab el Aziz = grains of Al-Aziz) named after the Fatimid ruler who was reputedly fond of it. References External links Flora of North America Flora of Europe Flora of Asia Flora of Africa Flora of South America Flora of the Caribbean Edible nuts and seeds esculentus Root vegetables Plants described in 1753 Taxa named by Carl Linnaeus