Nut of the Week - Hazelnuts

Hazelnuts, with shell (left), without shell (right)

A hazelnut is the nut of the hazel and is also known as a cob nut or filbert nut according to species. A cob is roughly spherical to oval, about 15–25 mm long and 10–15 mm in diameter, with an outer fibrous husk surrounding a smooth shell. A filbert is more elongated, being about twice as long as it is round. The nut falls out of the husk when ripe, about seven to eight months after pollination. The kernel of the seed is edible and used raw or roasted, or ground into a paste. Hazelnuts are also used for livestock feed, as are chestnuts and acorns. The seed has a thin dark brown skin, which is sometimes removed before cooking.

Hazelnuts are produced in commercial quantities in Turkey, Italy, Greece and in the American states of Oregon and Washington. Turkey is, by far, the largest producer of hazelnuts in the world.

Hazelnuts are used in confectionery to make praline, and also used in combination with chocolate for chocolate truffles and products such as Nutella. Hazelnut oil, pressed from hazelnuts, is strongly flavoured and used as a cooking oil.

Hazelnuts are rich in protein and unsaturated fat. Moreover, they contain significant amounts of thiamine and vitamin B6, as well as smaller amounts of other B vitamins.

Common hazel is widely cultivated for its nuts, including in commercial orchards in Europe, Turkey, Iran and the Caucasus. The name "hazelnut" applies to the nuts of any of the species of the genus Corylus. This hazelnut, the kernel of the seed, is edible and used raw or roasted, or ground into a paste. The seed has a thin dark brown skin, which has a bitter flavor and is sometimes removed before cooking. The top producer of hazelnuts, by a large margin, is Turkey, specifically the Ordu Province. Turkish hazelnut production of 625,000 tonnes accounts for approximately 75% of worldwide production.

In North America: in the United States, hazelnut production is concentrated in Oregon; they are also grown extensively just to the north, in the Fraser Valley of British Columbia, Canada. In 1996, the in-shell production in Oregon was about 19,900 tons, compared to 100 tons in Washington. Hazelnuts are also found in the Pangi valley of Chamba district in India, where they are known as thangi. The hazelnut is growing in popularity in the U.S., where the Hazelnut Marketing Board was established in 1949 by Federal Hazelnut Marketing Order section 982. The harvesting of hazelnuts is done either by hand or by manual or mechanical raking of fallen nuts.

There are many cultivars of the hazel, including 'Barcelona', 'Butler', 'Casina', 'Clark' 'Cosford', 'Daviana', 'Delle Langhe', 'England', 'Ennis', 'Fillbert', 'Halls Giant', 'Jemtegaard', 'Kent Cob', 'Lewis', 'Tokolyi', 'Tonda Gentile', 'Tonda di Giffoni', 'Tonda Romana', 'Wanliss Pride', and 'Willamette'. Some of these are grown for specific qualities of the nut; these qualities include large nut size and early and late fruiting cultivars, whereas others are grown as pollinators. The majority of commercial hazelnuts are propagated from root sprouts. Some cultivars are of hybrid origin between common hazel and filbert. One cultivar grown in Washington state, the "DuChilly", has an elongated appearance, a thinner and less bitter skin, and a distinctly sweeter flavor than other varieties.

Hazelnuts are harvested annually in mid-autumn. As autumn comes to a close, the trees drop their nuts and leaves. Most commercial growers wait for the nuts to drop on their own, rather than use equipment to shake them from the tree.

Hazelnuts are used in confectionery to make some pralines, in chocolate for some chocolate truffles, and in some hazelnut paste products (such as Nutella). In the United States, hazelnut butter is being promoted as a more nutritious spread than its peanut butter counterpart, though it has a higher fat content. In Austria and especially in Vienna, hazelnut paste is an ingredient in the making of tortes (such as Viennese hazelnut torte) which are famous there. In the Kiev cake hazelnut flour is used to flavor its meringue body and crushed hazelnuts are sprinkled over its sides. Hazelnuts are also the main ingredient of the classic Dacquoise liqueur. Hazelnut liqueurs, such as Frangelico, are Vodka-based.

Hazelnut-flavored coffee seems (to many users) to be slightly sweetened and less acidic, even though the nut is low in natural saccharides. The reason for such perception is not yet understood.

In Australia, over 2,000 tons are imported annually, mostly to supply the demand from the Cadbury company. Hazelnut oil, pressed from hazelnuts, is strongly flavored and used as a cooking oil. Hazelnuts are also grown extensively in Australia, in orchards growing varieties mostly imported from Europe. It is also grown in New Zealand and Chile.

Common hazel is used by a number of species of Lepidoptera as a food plant.

Hazelnuts have a significant place among the types of dried nuts in terms of nutrition and health because of the special composition of fats (primarily oleic acid), protein, carbohydrates, vitamins (vitamin E), minerals, dietary fibers, phytosterol (beta-cytosterol) and antioxidant phenolics such as flavan-3-ols.