Chufa

Despite the common name tiger nut, chufa is not a nut or a seed but a small underground tuber of a grass-like sedge that reaches about sixty centimetres, with three-sided stems and pale seed-heads. Each plant forms many round to oval tubers about one to two centimetres across, with a wrinkled brown skin and cream-coloured flesh.

The dried tubers are hard and wrinkled, soaked before eating to make them chewy and sweet, with a nutty, almond-like flavour. They are sold whole, peeled, as flour, as oil and as the milky drink horchata de chufa. The sedge is also a very persistent weed known as yellow nutsedge.

Chufa probably originated in the Mediterranean and Africa, and it has grown wild in warm regions across the Old World. Evidence of tiger nuts has been found in ancient Egyptian tombs, indicating that they were used as food and burial offerings for thousands of years.

The Spanish word chufa and the Valencian xufa have uncertain roots, while the name tiger nut is of unclear origin. Cyperus esculentus means edible sedge. In West Africa, the tubers are called aya in Hausa, and in Ghana atadwe, and they feature in local snacks and drinks.

Tiger nuts were eaten in ancient Egypt, where tubers have been found in tombs dating back to the predynastic era, and ancient writers described the plant. The Moors are said to have introduced the cultivation of chufa to the region of Valencia in Spain, where the drink horchata de chufa became a local tradition, sold in horchaterias and protected by a designation of origin, Chufa de Valencia.

In West Africa the tubers have long been a snack and are made into kunun aya, a creamy drink popular in northern Nigeria. In the Americas, wild nutsedge spread as an agricultural weed, and in the southern United States, it was among the most troublesome weeds in crops.

In the twenty-first century tiger nuts gained attention as a trendy gluten-free, nut-free, paleo-friendly snack and flour, with interest in prebiotic fibre. Spain remains a centre of production, with growing farms in West Africa as well. Because the plant can also be a damaging weed, farming is controlled in some regions.

Dried chufa tubers are soaked overnight and eaten as a chewy snack, ground into flour for baking, milled into oil, or blended with water, strained and sweetened to make horchata de chufa, a cold milky drink of Valencia. In Nigeria and Ghana, they are used for kunun aya and in sweets and snacks.

Toasted tubers have been used as a coffee substitute, and the flour suits gluten-free baking. Tubers are also eaten raw when fresh, and the plant's high fibre makes the flour useful as a thickener. Chufa also serves as wildlife feed and as bait.

Tiger nuts are high in dietary fibre, including resistant starch that can act as a prebiotic, and they provide oleic-rich oil, along with minerals such as potassium and magnesium. They are free from gluten and from tree nuts and peanuts, which makes them suitable for some people with allergies.

Evidence for specific health claims, such as better digestion or blood sugar control, comes mainly from small or laboratory studies. The high fibre and sugar content means they are best enjoyed in moderation, and horchata is often sweetened.