The air temperature should be 55°F or lower, and the air should be as dry as possible. Nuts stored under these conditions will not maintain quality for as long as those stored in a refrigerator or freezer. Whether storing nuts (walnuts, hazelnuts or chestnuts) or fresh chestnuts, the best option is to store them in the freezer or refrigerator. You can also store them in a cool room (55 degrees or below) if refrigeration is not possible.
After harvesting, the nuts must be dried for storage. It's easier to wait until the bunches are dry to remove the nuts from the bracts. Once the hazelnuts are dry, the meat will be firm and cream-colored. As long as the walnuts are not peeled, hazelnuts can be stored at room temperature for several months.
Shelled walnuts should be used within a few weeks or stored in the refrigerator, or frozen for up to a year. To prepare chestnuts for long-term storage, dry them following the instructions for walnuts and hazelnuts. Not only are they easy to harvest, but you'll never regret filling your kitchen with the scent of roasted hazelnuts. Serve this simple salad with arugula, bosc pears, dried currants and toasted hazelnuts at your next dinner, or enjoy it alone for a refreshing lunch.
Whether you grow your own tree or befriend a hazel bush in the woods behind your house, harvesting your own hazelnuts is sure to be very satisfying. If, like me, you can't refuse a pasta dish with a delicious nut pesto, try this vegan hazelnut pesto, it's delicious with tortellini. Cut the area around hazel trees to remove grass and weeds, which will make harvesting easier by allowing you to rake walnuts fallen into piles. If you need to remove your skin because the recipe says so, rub the hazelnuts with a rough cloth while they are hot.
Hazelnuts produce nuts when they are around 4 years old, but they don't become productive until they approach 7 years old. Harvesting hazelnuts means harvesting them as they fall from trees, before fall rains, if possible, said Ross Penhallegon, a horticulturist with the Extension Service at Oregon State University. Although the Oregon State University (OSU) Extension suggests keeping hazelnuts in shell in a closed container, I don't think that's necessary. Taste changes usually precede odor changes, so the normal smell of hazelnuts doesn't mean you're not out of danger yet.
During the summer months, the walnuts continue to ripen until the hazelnut harvest in October.