Pine nuts are naked seeds, not nuts, and a pinyon cone needs two summers
Botanically a pine nut is not a nut at all. Pines are gymnosperms, from the Greek for naked seed, so their seeds sit bare instead of inside a fruit. Of all the pine species, only 29 produce seeds big enough to be worth eating, and 20 of those are traded.
Europe's supply comes mostly from the stone pine, cultivated for its seeds for over 5,000 years, while people in Europe and Asia have eaten wild ones since the Paleolithic. Asia relies chiefly on the Korean pine, the most important species in world trade, and on the chilgoza pine of the western Himalaya. European kernels are long and slender; Asian ones are stubbier, shaped a little like corn kernels. China, Russia, North Korea and Pakistan export the most.
In North America the main sources are pinyon pines, whose seeds carry the Spanish name piñón. A pinyon cone starts as a marble-sized bud in spring, goes dormant through winter, and ripens only at the end of its second summer. Harvesters put the cones in burlap bags, leave them in the sun for about 20 days until they open, then bash the bags against a rough surface to shatter them. Crops do best between 1,800 and 2,600 metres; lower down, spring heat dries out the snowpack the tree depends on, and higher up, winter winds can freeze-dry the dormant cones.
Gathering is bound up with the Native American and Hispano communities of the Southwest, among them the Shoshone, Paiute, Navajo and Hopi. Treaties and Nevada law guarantee the right to harvest, New Mexico protects the word piñon for certain native pines, and some California tribes burn basket designs into the shells and wear them as beads.
Once shelled, the seeds, which are 68 percent fat, go rancid within weeks, or days in warm humid weather, so they are often frozen. Between 2008 and 2012 some Americans reported a bitter, metallic taste that lingered for weeks, dubbed pine mouth; an FDA investigation found that some suppliers had substituted a non-food pine species for pricier edible ones. In kitchens they anchor Italian pesto, Catalan panellets and Levantine dishes from kibbeh to baklava.
Source: Pine nut
