What Are Hazelnuts? A Complete Guide to This Crisp, Fragrant Nut

Hazelnuts are the fruit of the hazel tree, a plant in the genus Corylus of the birch family. They are a familiar edible nut, also known as mountain chestnut or chui zi. Hazel trees are mostly deciduous shrubs or small trees with nearly round leaves that have serrated edges. The fruit is wrapped in a husk, and when ripe the shell is hard, while the kernel inside is plump and crisp with a distinctive aroma.

Hazelnut kernels are fairly rich in oils and protein, and also contain a variety of minerals and vitamins. Once roasted, they have an intense flavor and are a very popular snack nut. Hazelnut kernels are also an important raw material in food processing, often used to make pastries, chocolate, candy and more, and they can also be pressed to extract hazelnut oil, making their uses extremely wide-ranging.

In terms of varieties, China has wild Ping hazel (Corylus heterophylla) and Manchurian hazel (Corylus mandshurica), as well as introduced and cultivated European hazel (Corylus avellana), and also Ping-European hybrid hazels bred by crossing Ping hazel with European hazel. These hazelnuts have larger fruit and are often called large-fruited hazelnuts. Wild hazelnuts mostly grow in the mountainous areas of Northeast China and North China, and in recent years the area under artificial cultivation has continued to expand.

Hazel trees are highly adaptable, cold-tolerant and tolerant of poor soil, and they prefer environments with ample sunlight and good drainage, making them suitable for planting on gentle slopes, plains or in courtyards. Seedlings grown from seed enter the fruiting stage relatively late, while seedlings propagated by vegetative methods such as grafting and division can flower and bear fruit earlier, so the latter is mostly used to establish orchards in production.