Hazelnuts

Hazelnuts drop from the tree when ripe, and the crop is collected from the orchard floor by sweeping and mechanical pickup, or by hand where terrain rules out machinery. The nuts are then dried, and either traded in-shell or cracked to yield kernels. In-shell hazelnuts serve a seasonal retail trade, but the volume flows as kernels, because the industrial buyers who dominate demand want kernels.

Cultivar has direct commercial consequences. Round kernels are preferred by confectionery manufacturers because they embed and coat evenly, size uniformity determines how a batch roasts, and cultivars differ markedly in how readily the pellicle releases. A cultivar with an excellent flavour and a stubborn pellicle is a commercially awkward hazelnut.

Collecting nuts from the ground means collecting whatever they have been lying in. Nuts that sit on damp soil take up moisture, stain, and can begin supporting mould growth, and the interval between fall and collection is therefore a quality variable in the way that the interval between harvest and hulling is for pistachios. Wet seasons compress that window sharply.

Drying follows collection and brings the nuts to a moisture at which they are stable in store. Hazelnuts, like other tree nuts, carry a mould and mycotoxin risk in inadequately dried lots, and the ground-contact harvest is precisely why that risk requires management. Once dry, the commodity behaves like other stored nuts: the shell affords protection, kernels are more exposed, and the eventual limit is rancidity in an oil-rich kernel rather than microbial spoilage.

Kernel lots are specified on size and size uniformity, shape, colour, moisture, and defect incidence, with roasting behaviour and pellicle removal assessed on samples. In-shell lots are additionally judged on shell condition, cleanliness, and the proportion of well-filled nuts. Blanks — nuts whose kernel never developed — are a defect that cannot be seen from outside and are removed by density separation.

• Blank and poorly filled nuts
• Mould growth and mycotoxin risk in lots collected wet or dried late
• Insect damage, including nuts damaged on the tree before fall
• Rancidity in kernels held warm, bright, or long
• Shrivelled, misshapen, and undersized kernels
• Poor pellicle release after roasting

Grade standards for hazelnuts are jurisdictional and versioned, and much of the trade also runs on contract descriptions written by industrial buyers to their own processing requirements — which can be more demanding, and more specific, than any public grade.

Confectionery is the destination for most of the crop: kernels roasted, skinned, and then whole, chopped, or ground into pastes for chocolate, spreads, and bakery. A smaller share reaches consumers as snack nuts and as in-shell nuts in seasonal retail. Kernels are pressed for hazelnut oil in modest quantities for culinary and cosmetic use, and shells from cracking are used as fuel and as a mulch and abrasive material.

• Food — kernels for confectionery, spreads, and bakery, the dominant outlet
• Food — whole and in-shell nuts for the snack and seasonal retail trade
• Oil and industrial — hazelnut oil, and shells used as fuel, mulch, and abrasive