Korean Pepper Tree (Chopi)

Health Benefits

What the Donguibogam records — nature, taste, names and preparation. The Donguibogam lists the tree in the Wood section as 蜀椒. It gives a hot nature, a pungent taste and toxicity, with one source calling the toxicity slight. It describes a tree four or five cheok tall, like cornel but smaller and thorny, and records that in the fourth lunar month fruit sets among the leaves without flowers, round like small beans with a purplish-red skin. The fruit is gathered in the eighth lunar month and dried in shade, and the entry adds the alternative names 川椒, 巴椒 and 漢椒. For preparation it directs removing the 目 and discarding fruit whose mouth stays shut. Which tree the old name 蜀椒 stood for varies from record to record: Chinese materia medica generally reads it as huajiao (Zanthoxylum bungeanum), while Korean records also attach the name to the chopi tree. This is a historical medical record and differs from modern medical judgment.

Compositional work on the tingling sensation. Compositional analyses report that the tingling of chopi comes from hydroxy-alpha-sanshool and related amides. The same work describes a mechanism distinct from that of capsaicin in chilli. This concerns sensation and composition, and has nothing to do with preventing or treating disease.

蜀椒 and 秦椒 split by growing region. The same entry separates the two by origin, calling the Sichuan product 蜀椒 or 川椒 and the Guanshaan product 秦椒. It gives 秦椒 a warm nature and a pungent taste, with one source calling it bitter, and records toxicity. Leaves, stems and fruit are said to resemble 蜀椒 but with a shorter taste, smaller fruit and a yellow-black colour, gathered in the eighth or ninth lunar month. This is a historical medical record and differs from modern medical judgment.

Nutrition

• Hydroxy-alpha-sanshool (concentrated in the fruit husk) — produces the tingling, numbing sensation on the tongue
• Essential oil (limonene, citronellal and others) (released as soon as the husk is rubbed) — volatile compounds behind the distinctive scent
• Fixed oil (concentrated in the black seed (椒目)) — grinding the seeds in adds bitterness and an oily smell

Sanshool and the tingling sensation The tingle of chopi is a different thing from chilli heat. Analyses report that hydroxy-alpha-sanshool and related amides act on touch-side nerves, which is why the sensation reads as numbness rather than burning. The compounds are heat-sensitive, so long boiling dulls the effect. That is why chopi powder goes in at the table, after the heat is off.

The essential oil The fruit husk holds an essential oil in which limonene and citronellal have been reported. Being volatile, it disperses quickly once the husk is ground. Keeping the fruit whole and grinding small amounts as needed holds the scent far longer. Any powder already ground belongs in a sealed jar in the freezer.

Why husk and seed are separated Only the husk is used; the black seeds are picked out. The seeds are rich in fixed oil, and grinding them in lays bitterness and an oily smell over the dish. The Donguibogam also instructed removing the 目 when preparing 蜀椒, and 目 here means the seed. Well-dried fruit splits open when rubbed between the palms, and the seeds fall free.

Pairings

○ Chueotang and freshwater fish stew — Chopi powder has long been used to cover the muddy note of freshwater fish. Added to the pot it loses its scent, so it is served at the table for each person to stir in. A pinch per bowl is plenty.

○ Kimchi and pickles — Southern kimchi pastes often take chopi leaves or powder. The scent is strong enough that a very small amount does the work; too much and the kimchi tastes only of chopi. Young leaves are also pickled in soy as a side dish.

○ Tofu and dressed greens — Used alongside sesame oil, the scent spreads evenly through the dish. It fades if the dish sits, so serve it straight away. The aroma carries the dish without heavy salting.

△ Unopened fruit and black seeds — The Donguibogam instructed removing the 目 and discarding fruit whose mouth stays shut, adding that closed-mouth fruit kills. The wording belongs to its time, but read as a handling rule about discarding unripe or spoiled fruit it still holds. Properly dried fruit has already split open. Throw out anything still closed, along with the black seeds.

△ Numbness from too much — Because the tingle acts on nerves, going past a small dose leaves the mouth numb for a long while and dulls other flavours. The working amount is a pinch per serving. Start at half that and work up. Leave it out of a child's bowl and let them add it themselves.

△ Confusion with sancho — Sancho (Zanthoxylum schinifolium) is a different species with a different scent, grown mainly for seed oil. Chopi carries paired thorns at each node while sancho's alternate, which is the reliable check. Powder sold as sancho in Korean markets is sometimes chopi, so confirm by smell. Anyone foraging should settle the identification before picking. Sancho (Shiny-leaf Prickly Ash)

Varieties

• Chopi (jepi) (sapling) — The southern native line. Paired thorns at the nodes and strongly scented leaves
• Wang-chopi (sapling) — Grows on Jeju and the south coast. Broader leaves and thicker thorns
• Sancho (sapling) — A separate species (Zanthoxylum schinifolium). Alternate thorns, and the seeds are pressed for oil. Frequently confused with chopi