Korean Chili Peppers (Fresh)

Chili peppers (Capsicum annuum) are native to the Americas and reached Korea only in the early 17th century. The Encyclopedia of Korean Culture points to Yi Su-gwang's Jibong yuseol, which calls the pepper a ‘Japanese mustard’ that had come from Japan, while noting that later exchanges with China and local breeding also shaped Korea's peppers. Farmers saved their own seed for generations, so by the 20th century there were roughly a hundred local types, many named for the place they grew, such as Yeongyang, Cheongsong, Imsil and Jeju.

The same plant gives two harvests. Green peppers for eating fresh are picked about two weeks after flowering, before they ripen; peppers for drying are left about fifty days until red. Much of the fresh supply is now grown under plastic in winter, while field crops are dried for gochugaru. Traditional ways with green peppers include eating them raw with a dab of gochujang or doenjang, stuffing halves with tofu or beef for jeon, and pricking whole peppers and pickling them in salted-fish brine for winter, the forerunner of gochu-jangajji.

Cheongyang-gochu, Korea's benchmark hot pepper, is surprisingly young. The Encyclopedia of Korean Culture and the Digital Cheongsong Culture Encyclopedia both credit Jungang Seed Company, with breeder Yu Il-woong, with developing it in 1983 as a hybrid of a Thai landrace and a Jeju landrace. It was first bred to supply capsaicin for curry production; when that proved uneconomic, the leftover seed went to trial farmers in Cheongsong and Yeongyang in North Gyeongsang, who found it excellent in spicy fish stews and sold well. The name joins the first syllable of Cheongsong (靑) with the second of Yeongyang (陽), not the county of Cheongyang in South Chungcheong.

Kkwari-gochu sits at the other end of the scale. Korea's agrifood information service describes it as smaller, paler green and sweeter than other peppers, with a crinkled, glossy skin and few seeds, in season in July and August, with Yeoju, Dangjin, Yeongam and Jangseong among its growing areas. Its folds hold sauce, which is why it is braised with soy sauce and stir-fried with dried anchovies.

• Vitamin C: Per 100 g, raw green peppers in the Korean Food Composition Table supply roughly 44–57 mg of vitamin C depending on type, along with beta-carotene and potassium.
• Capsaicin: The heat comes from capsaicin, concentrated in the pale ribs that hold the seeds rather than in the seeds themselves. The Encyclopedia of Korean Culture notes that Korean kimchi peppers carry less capsaicin and more sugar than Tabasco-type peppers. Research on capsaicin and health is ongoing.
• How hot is hot: The Encyclopedia of Korean Culture puts cheongyang-gochu at roughly 33,000–37,000 Scoville units on a dry-weight basis, and notes that heat varies with growing conditions: hot, dry seasons make hotter peppers.
• Vitamin K: Green peppers contain vitamin K (about 52–76 µg per 100 g in the Korean table). People taking warfarin are generally advised to keep their intake of vitamin K–rich foods steady rather than avoid them.
• Sensitivity: Hot peppers can aggravate heartburn or digestive discomfort in some people, and capsaicin irritates eyes and skin; wash hands after cutting.