Hazelnut

Thehazelnutis thefruitof thehazel treeand therefore includes any of the nuts deriving from species of the genusCorylus, especially the nuts of the speciesCorylus avellana.They are also known ascobnutsorfilbertsaccording to species.
Hazelnuts are used as asnackfood, inbakinganddesserts, and in breakfast cereals such asmuesli. Inconfectionery, they are used to makepraline, and also used in combination withchocolateforchocolate trufflesand products such as chocolate bars and hazelnut cocoa spreads such asNutella. They are also used inFrangelicoliqueur.Hazelnut oil, pressed from hazelnuts, is strongly flavored and high inmonounsaturated fat. It is used as a cooking oil and as a salad or vegetable dressing.
Turkeyis the world's largest producer of hazelnuts, accounting for 58% of total production in 2023.
A hazelnut cob is roughly spherical to oval, about15–25 millimetres (5⁄8–1 inch) long and10–15 mm (3⁄8–5⁄8in) in diameter, with an outer fibroushusksurrounding a smooth shell, while a filbert is more elongated, being about twice as long as its diameter. The nut falls out of the husk when ripe, about seven to eight months after pollination. Theseedis edible and consumed raw, roasted or ground into a paste. The seed has a thin, dark brown skin, which is sometimes removed before cooking.
In 1995, evidence of large-scaleMesolithicnut processing, some 8,000 years old, was found in amiddenpit on the island ofColonsayin Scotland. The evidence consists of a large, shallow pit full of the remains of hundreds of thousands of burned hazelnut shells. Hazelnuts have been found on other Mesolithic sites, but rarely in such quantities or concentrated in one pit. The nuts wereradiocarbon datedto 7720±110 BP, which calibrates toc.6000 BCE. Similar sites in Britain are known only atFarnhaminSurreyand Cass ny Hawin on theIsle of Man.
This discovery gives an insight into communal activity and planning in the period. The nuts were harvested in a single year, andpollen analysissuggests that all of thehazeltrees were cut down at the same time.
The scale of the activity and the lack of large game on the island suggest that Colonsay may have contained a community with a largely vegetarian diet for the time they spent on the island. Originally, the pit was on a beach close to the shore and was associated with two smaller, stone-lined pits whose function remains obscure, a hearth and a second cluster of pits.
The traditional method to increase nut production is calledbrutting, which involves prompting more of the tree's energy to go into flower bud production by snapping, but not breaking off, the tips of the new year shoots six or seven leaf groups from where they join with the trunk or branch, at the end of the growing season.The traditional term for an area of cultivated hazelnuts is aplat.
The manycultivarsof the hazel include 'Atababa', 'Barcelona', 'Butler', 'Casina', 'Clark', 'Cosford', 'Daviana', 'Delle Langhe', 'England', 'Ennis', '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, including large nut size or early or late fruiting, whereas others are grown as pollinators. The majority of commercial hazelnuts are propagated from root sprouts.Some cultivars are ofhybridorigin betweencommon hazelandfilbert.
In Ireland and the United Kingdom, hazelnuts are sometimes referred to as cobnuts, for which a specific cultivated variety – Kentish cobnuts – is the main variety cultivated in fields known as plats, hand-picked, and eaten green.According to the BBC, a national collection of cobnut varieties exists at Roughway Farm, nearPlaxtolin Kent.They are called cobnuts because cob was a word used to refer to the head or "noggin,” and children had a game in which they would tie a string to a hazelnut and use it to try to hit an opponent on the head.
In Europe hazelnuts are traditionally grown as multi-trunk trees where the rootstock is formed by the variety itself. To enhance the possibility for mechanization and to preventsuckering, a single-trunk tree can be formed bygraftinga scion of the desired variety on aCorylus colurnarootstock.There are different approaches in orchard floor management. Strong infestations of certain weeds can lower the yield. Therefore, to prevent yield loss by competition, herbicides are used to create bare soil.Using cover crops protects the soil and suppresses weed establishment without a yield reduction.
Silvopastoral systemswhere animals likepigsare kept in the orchard orsilvoarable systemswhere crops are grown between the rows could introduce new sources of revenue into the hazelnut production and may have beneficial effects on hazelnut yield by fertilizing the soil through nitrogen fixation or animal dung. These systems limit the plant protection measures, potentially impacting the yield quality and level.There are very few studies on these systems, leading to a higher uncertainty for the producer.
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 rather than using equipment to shake them from the tree. The harvesting of hazelnuts is performed either by hand or by manual or mechanical raking of fallen nuts.
Four primary pieces of equipment are used in commercial harvesting: the sweeper, the harvester, the nut cart, and the forklift. The sweeper moves the nuts into the center of the rows, the harvester lifts and separates the nuts from any debris (i.e., twigs and leaves), the nut cart holds the nuts picked up by the harvester, and the forklift brings a tote to offload the nuts from the nut cart and then stacks the totes to be shipped to the processor (nut dryer).
The sweeper is a low-to-the-ground machine that makes two passes in each tree row. It has a 2 m (6 ft 7 in) belt attached to the front that rotates to sweep leaves, nuts, and small twigs from left to right, depositing the material in the center of the row as it drives forward. On the rear of the sweeper is a powerful blower to blow material left into the adjacent row with air speeds up to 90 m/s (300 ft/s). Careful grooming during the year and patient blowing at harvest may eliminate the need for hand raking around the tree trunk, where nuts may accumulate. The sweeper prepares a single center row of nuts, narrow enough for the harvesting tractor to drive over without driving on the center row. It is best to sweep only a few rows ahead of the harvesters at any given time, to prevent the tractor that drives the harvester from crushing the nuts that may still be falling from the trees. Hazelnut orchards may be harvested up to three times during the harvest season, depending on the number of nuts in the trees and the rate of nut drop due to the weather.
The harvester is a slow-moving machine pushed by a tractor, which lifts the material off the ground and separates the nuts from the leaves, empty husks, and twigs. As the harvester drives over the rows, a rotating cylinder with hundreds of tines rakes the material onto a belt. The belt takes the material over a blower and under a powerful vacuum that sucks any lightweight soil, leaves from the nuts, and discharges them into the orchard. The remaining nuts are conveyed into a cart pulled behind the harvester. Once a tote is filled with nuts, the forklift hauls away the full totes and brings empty ones back to the harvester to maximize the harvester's time.
Two different timing strategies are used for collecting the fallen nuts. The first is to harvest early when about half of the nuts have fallen. With less material on the ground, the harvester can work faster with less chance of a breakdown. The second option is to wait for all the nuts to fall before harvesting. Although the first option is considered the better of the two,two or three passes do take more time to complete than one.
In 2023, world production of hazelnuts (in shells) was 1.13 milliontonnesled by Turkey with 58% of the total, and Italy and the United States as other major producers (table).
Hazelnuts are used inconfectionsto makepralines,chocolate truffles, and hazelnut paste products. The (solid) combination of ground hazelnuts with chocolate is calledgianduja.InAustria, hazelnut paste is an ingredient for makingtortes, such as Viennese hazelnut torte. InKyiv cake, hazelnut flour is used to flavor itsmeringuebody, and crushed hazelnuts are sprinkled over its sides.Dacquoise, a French dessert cake, often contains a layer of hazelnut meringue. Hazelnuts are used inTurkish cuisineandGeorgian cuisine; thesnackchurchkhelaand saucesatsiviare used, often withwalnuts. Hazelnuts are also a common constituent ofmuesli. The nuts may be eaten fresh or dried, having different flavors.
Raw hazelnuts are 5% water, 61%fat, 17%carbohydrates, and 15%protein(table).
In a100-gram (3+1⁄2-ounce) reference amount, raw hazelnuts supply 2,630 kilojoules (628 kilocalories) offood energyand are a rich source (20% or more of theDaily Value, DV) of numerousessential nutrients(see table).
Hazelnuts contain particularly high amounts ofprotein,dietary fiber,vitamin E,iron,thiamin,phosphorus,manganese, andmagnesium, all exceeding 30% DV (table). SeveralB vitaminshave appreciable content. In lesser but still significant amounts (moderate content, 10–19% DV) arevitamin K,calcium,zinc, andpotassium(table).
Hazelnuts are a rich source of dietaryfat, accounting for 93% DV in a 100-gram amount. The fat components aremonounsaturated fatasoleic acid(75% of total),polyunsaturated fatmainly aslinoleic acid(13% of total), andsaturated fat, mainly aspalmitic acidandstearic acid(together, 7% of total).
The hazelnut is used as a literary device byJulian of Norwich(c. 1343 – after 1416) within her mystical Christian treatiseRevelations of Divine Love.The hazelnut shell is imagined as a chariot for the fairyQueen Mabwithin English playwright and poetWilliam Shakespeare'splayRomeo and Juliet. The hazel fruit is also used as a metaphorical device in the poemTo Autumnby theEnglish RomanticpoetJohn Keats.