Hazelnut

The hazelnut is the edible fruit of trees within the genus Corylus.

These nuts are highly valued globally for their rich flavor and nutritional density. They are used in many ways, ranging from simple snack foods to complex confectionery. People enjoy them in breakfast cereals like muesli or as part of various desserts. In many cultures, the nut is a staple ingredient in both sweet and savory cooking. The hazelnut is more than just a food; it is a major global commodity.

A hazelnut begins its life as a seed protected by a fibrous outer husk.

The nut is roughly spherical or oval, whereas a variety called a filbert is more elongated. About seven to eight months after pollination, the nut becomes ripe and falls from its husk. The edible seed inside features a thin, dark brown skin. Depending on the specific cultivar, the nut can make up between 33.2% and 49.5% of the total fruit. Cultivars grown near the Mediterranean Sea often have the highest nut-to-fruit ratio.

Commercial growers use specific methods to manage these trees and increase yields. One traditional technique is called brutting, which helps the tree produce more flower buds. To do this, farmers snap the tips of new shoots at the end of the growing season. In Europe, many orchards use a multi-trunk growing system. However, some producers graft a desired variety, called a scion, onto a Corylus colurna rootstock to create a single-trunk tree. This makes it easier to use large machinery in the orchard. Some farmers also use silvopastoral systems, where animals like pigs live among the trees to fertilize the soil.

Harvesting is a precise process that usually takes place in mid-autumn.

Most commercial growers wait for the nuts to drop naturally from the trees. To collect them, farmers use four primary pieces of equipment: sweepers, harvesters, nut carts, and forklifts. A sweeper is a low machine that moves nuts and leaves into the center of the orchard rows.

Next, a tractor-driven harvester lifts the material from the ground. It uses a rotating cylinder with tines to rake the nuts onto a belt. A vacuum then sucks away lightweight debris like soil and leaves. Finally, the cleaned nuts are moved into carts for transport.

Human history with the hazelnut stretches back thousands of years.

In 1995, archaeologists found evidence of large-scale nut processing on the island of Colonsay in Scotland. They discovered a midden pit containing hundreds of thousands of burned hazelnut shells. These shells were radiocarbon dated to approximately 7720 years old. This massive find suggests that Mesolithic communities engaged in organized, communal harvesting. Because large game was scarce on the island, these people likely relied on a largely vegetarian diet. Similar ancient sites have also been found in Surrey, England, and on the Isle of Man.

Today, the hazelnut industry is a massive global operation. In 2023, the world produced 1.13 million tonnes of hazelnuts in their shells. Turkey was the leading producer, accounting for 57.7% of the total global supply. Italy and the United States are also major contributors to the market. In the United States, production is concentrated almost entirely in the Willamette Valley of Oregon. The nuts are incredibly nutritious, containing high levels of protein, dietary fiber, and vitamin E. They are also a significant source of monounsaturated fats, specifically oleic acid.

Culturally, the hazelnut appears in many famous works of art and literature. In the play Romeo and Juliet, William Shakespeare describes a hazelnut shell as a chariot for the fairy Queen Mab. The poet John Keats also used the fruit as a metaphor in his poem "To Autumn." In the culinary world, the nut is essential for making pralines and chocolate truffles. In Italy, the combination of ground hazelnuts and chocolate led to the creation of Nutella. From French Dacquoise cakes to Turkish churchkhela, the hazelnut remains a versatile and beloved part of human culture.