The hazelnut, also known as the filbert, is a nutritious tree nut crop that can be successfully harvested and preserved at home. Understanding the proper timing and post-harvest steps is crucial to maximize both the yield and the quality of the nuts. The process involves recognizing maturity, gathering the nuts, removing the outer husk, and drying them to achieve a stable, long-lasting product. Following these methods ensures your harvested hazelnuts maintain their rich flavor and crisp texture.
Identifying the Optimal Harvest Time
The precise moment for harvest is signaled by a series of natural changes in the nut and its surrounding husk. Hazelnuts generally reach maturity and begin to drop from the tree starting in late August and continuing through October. This natural falling is the most reliable indicator that the kernels have fully ripened and developed their flavor.
Visually, the leafy outer casing, or involucre, transitions from a vibrant green to a dry, papery brown color. The nuts themselves darken to a rich brown hue as the kernel inside fully develops. You can confirm ripeness by checking if the nuts are loose and easily fall out of the husk when gently touched. The overall ripening period for a single tree can last up to six weeks, meaning the harvest will be staggered.
Gathering and Collection Methods
Because ripe hazelnuts naturally fall to the ground, the primary collection method involves gathering them from the orchard floor. Before the nuts begin to drop, it is helpful to mow the area underneath the trees to create a clean surface. This preparation prevents the nuts from becoming lost in long grass or moist soil, which can lead to mold and spoilage.
For small backyard yields, a simple rake or broom can be used to sweep the nuts into piles for manual collection. Another practical option is a handheld rolling tool, often called a nut gatherer, which picks up fallen nuts by rolling over the ground. For larger orchards, mechanical collection becomes necessary to efficiently cover the area.
Commercial growers use specialized equipment, such as mechanical sweepers or vacuum harvesters, to collect the nuts from the prepared ground. If mature nuts are still clinging to the branches, a gentle shaking of the limb can encourage the ripe ones to drop. This technique should only be applied to branches where the husks have already started to brown, ensuring only mature nuts are collected.
Immediate Post-Harvest Processing
Once the nuts are gathered, the first task is to process them quickly to prevent quality degradation. The leafy or papery husk surrounding the shell must be removed in a process known as hulling. Hulling is necessary because the husks retain moisture, and leaving them attached can create an environment where mold and rot can rapidly develop.
For small batches, the husks can often be stripped away by hand, especially if they are dry and brittle. An effective low-tech method involves placing the nuts in a durable bag, such as a burlap sack, and rubbing or walking on them to mechanically separate the nut from the husk. Small-scale mechanical devices, like a bucket husker, are also available for home growers.
After hulling, an initial cleaning step is needed to separate the nuts from large debris like sticks, leaves, and stones collected from the ground. This can be done by hand sorting or by gently pouring the mixture in front of a fan to blow away the lighter husk fragments and leaves. Any remaining debris should be removed before proceeding to the curing process.
Curing and Long-Term Storage
Curing is the drying process that reduces the moisture content of the nuts to a level suitable for long-term preservation. This moisture reduction develops the characteristic crunchy texture and concentrated flavor of the hazelnut kernel. The goal is to lower the internal kernel moisture to approximately 6%, which prevents the growth of mold and slows the onset of rancidity.
The hulled hazelnuts should be spread out in a single layer on a screen or mesh tray to ensure maximum air circulation around each shell. This setup should be placed in a warm, dry area that is well-ventilated, such as a garage, attic, or covered porch. The nuts must be stirred daily during the curing period to promote even drying and prevent any moisture pockets from forming.
Natural air-drying typically takes between two and four weeks, depending on the ambient temperature and humidity levels. Once fully cured, the unshelled hazelnuts can be stored in breathable containers, like mesh bags or perforated boxes, in a cool, dark location where the temperature remains below 10°C. For maximum freshness, or for shelled kernels, storage is best achieved in an airtight container placed in a refrigerator for up to one year or in a freezer for an even longer duration.