Pine nuts

Jat are the seeds of the Korean pine, Pinus koraiensis, a tall evergreen with needles in bundles of five and large cones holding some eighty to ninety wingless seeds each. Older names include baekja and silbaek. Chinese herbals from the Tang and Ming dynasties recorded pine nuts as a product of Silla — the Ming Bencao gangmu calls them "Silla pine seeds" — and Silla sent them to China as gifts.

Gapyeong pine nuts appear as a local product of Gapyeong county in the 15th-century geography of the Sejong sillok and were sent as royal tribute; the Joseon court gave pine nuts to China and Japan by the hundreds of geun. Harvesting is still hard work. Pickers climb the trees and pull cones down with hooked poles, then the cones are dried, threshed for the hard-shelled seeds, dried again and shelled to free the white kernels. Gapyeong, where roughly a quarter of the forest is Korean pine, produced an average of about 1,600 tons a year between 2010 and 2021 — close to 39 percent of the national harvest — though yields are falling with hotter summers, pests and aging trees.

Pine nuts are mostly a garnish in Korean cooking: floated on sujeonggwa and sikhye, set on gujeolpan, sinseollo and braises, pressed into yaksik, and bound with syrup into yeot-gangjeong. Ground with rice they make jatjuk, long given to the sick and elderly, and there is a Jeongwol Daeboreum custom of threading twelve nuts on a needle and lighting them to read the luck of each month by how brightly they burn.

• Mostly unsaturated fat: Pine nuts are about two-thirds fat by weight, largely unsaturated fatty acids such as oleic and linoleic acid, and are energy-dense.
• Minerals and vitamin E: The Korean Food Composition Table lists them as very high in manganese and rich in magnesium, zinc and vitamin E.
• A labeled allergen in Korea: Pine nuts are classed as a tree nut in Korea and must be declared on food labels; they are among the triggers of food allergy in Korean children.
• "Pine mouth": Some people develop a bitter or metallic taste lasting days to weeks, starting a day or two after eating pine nuts. An FDA investigation of 501 U.S. reports linked it to nuts from the Chinese white pine (Pinus armandii), not the Korean pine; it resolved without lasting harm, and the cause is still unknown.