Kukui Nut

The kukui or candlenut tree is a fast-growing evergreen, up to about 20 metres, with pale, silvery-green foliage and clusters of small white flowers. The fruit is a rounded, fleshy green husk that contains one or two nuts. The nut has a very hard, rough, dark shell about 4 to 5 cm across, enclosing a creamy white, oily kernel. Raw kernels are waxy and bitter and are mildly toxic, and they must be cooked before eating. Roasted or toasted, the kernel has a mild, rich flavour, similar to macadamia. It is sold as whole shelled nuts, ground paste and cold-pressed oil, and polished shells are made into leis and jewellery.

Aleurites moluccanus probably originated in Southeast Asia or the Pacific region, though its exact native range is uncertain because the tree was spread so widely by early seafarers. Polynesian voyagers carried it to Hawaii, where it became naturalised and is known as kukui. The name candlenut comes from the use of the oily nuts as candles, and kemiri is the Indonesian and Malay name. The genus name Aleurites comes from a Greek word meaning floury, referring to the dusty texture of the leaves, and moluccanus refers to the Moluccas.

Candlenut has been carried across the Indo-Pacific for thousands of years. In Hawaii, it was one of the most important canoe plants, providing light, as nuts were strung on a stick and burned one after another, oil for lamps and for caulking canoes, dye from the bark, and the nuts were used as relish. Roasted and mashed kernels, called inamona, are a traditional Hawaiian condiment served with fish and poke. The kukui was named the state tree of Hawaii in 1959, symbolising enlightenment and protection. In Indonesia and Malaysia, kemiri is a crucial ingredient in curries and sauces, thickening and enriching spice pastes. Across the Pacific, the oil was used for skin and hair, and the nuts were used in games, necklaces and ceremonies. The tree has also been planted widely as an ornamental and for erosion control in tropical regions, and has become invasive in some places. Kukui oil is now an ingredient in cosmetics and sometimes in drying oil products such as varnishes.

In Indonesian, Malaysian and Hawaiian cooking, the kernels are toasted and ground into spice pastes for curries, sambals and sauces, giving body and a mild nutty flavour; macadamias are often used as a substitute. Inamona, a Hawaiian relish, is made by roasting and pounding the kernel with salt. The oil is used in skin and hair care, as massage oil, for lighting and, historically, for wood finishing. The shells are polished and strung as leis and jewellery, and the wood is used for light construction.

Candlenut kernels are high in fat, including polyunsaturated fatty acids, and are eaten in small amounts as a flavouring. Traditional medicine uses the oil and other parts for skin conditions and as a laxative, but there is little clinical evidence for any medicinal effects. Raw kernels should not be regarded as a health food.