Sancho (Shiny-leaf Prickly Ash)

Zanthoxylum schinifolium

Essential oils (limonene, citronellal) · a tree pressed for its seed oil

Sancho is a deciduous shrub in the citrus family, and it is not the same plant as chopi, the tree it is usually lumped with in Korea. Sancho carries its prickles alternately below the leaf stalk and flowers late, in August or September; chopi carries paired prickles and flowers in April or May. Note also that the Japanese spice called sansho comes from Zanthoxylum piperitum, which is closer to chopi than to this tree. In a city, planting one sapling in a yard corner and waiting three or four years is more realistic than a pot, after which the black ripe fruit is shaken down and pressed for oil. The Donguibogam lists it in the Wood section as 秦椒, records the Korean name as bundi, and explains that fruit from the Qin region is called 秦椒 while fruit from Sichuan is 蜀椒 or 川椒, gathered in the eighth or ninth lunar month.

Year-Round Calendar

Sowing

Harvest

Where It Grows

Main producer Wild population Latitudes at 18–25℃ Zoom and pan to explore · temperatures are rough zonal averages

Main producer It grows wild on foothills nationwide, and in the southern mountain districts the fruit is gathered and pressed for oil. This is just about the only country where cultivation for the fruit survives. Harvest September, October
9. 9
10. 10
Wild population It grows wild in the mountains from North China down to South China, where it is used under the name xiangjiaozi.
Wild population It grows wild in the mountains from Honshu southward. The spice Japan calls sansho and actually uses, however, is the chopi tree.

The tree grows wild on the lower mountain slopes of Korea, China and Japan, and no single country can be named as its origin. Several spices share overlapping names, so the species has to be stated when the range is shaded on a map: Japan's sansho is chopi, Zanthoxylum piperitum, and the huajiao of Sichuan cooking in China is hwacho, Z. bungeanum, both of them different species from sancho, Z. schinifolium.

Optimum: 18~25℃
Range: 5~32℃
Hardiness: Hardy

A deciduous shrub that drops its leaves in winter, it endures even the cold of Korea's central inland. Sunny, free-draining slopes at the foot of a mountain suit it best, and its roots spoil easily if they sit in water.

Harvested 3–4 years after planting. A seedling needs three or four years in the ground before it bears properly. There is little fruit to be had in the year it is planted, and once the tree has settled in it is picked every year in September and October.

In Korea Nationwide

It grows wild on foothills and near villages across the country, and in the mountain districts of the south and the central inland the fruit is gathered and pressed for oil.

How to grow

Light: Five hours of direct sun or more. It survives in part shade but sets little fruit
Soil and depth: Free-draining sandy loam. The roots rot quickly if they sit in water
Spacing: Two to three metres between trees. A mature plant spreads to around three metres tall
Watering: Water through the first summer only. Once established, watch only for waterlogging in the rainy season and midsummer drought
Feeding: A spadeful of well-rotted compost around the trunk in early spring. Too much nitrogen pushes long shoots and fewer fruit
Harvest: Cut whole fruiting branches when the fruit has blackened and the husks start to split, then dry them in the shade. As they dry the husks open and the black seeds drop out, leaving the aroma in the husk. This falls in September and October, broadly overlapping the eighth to ninth lunar month given in the old text

What makes the difference. The prickles are thick and unforgiving. Wear heavy leather gloves for harvest and pruning, and clear cut branches away immediately so nobody steps on them

Why this one is harder. Seed is difficult to germinate. Wash the oil off autumn-collected seed and overwinter it mixed into damp sand before it will sprout the following spring. For a first tree, buying a sapling is far easier

Common problems

Swallowtail caterpillars You will see Whole leaves disappear and fat caterpillars sit on the branches What to do They feed on citrus-family leaves, so sancho attracts them. A mature tree can carry them; on a young sapling, move them off by hand
Aphids You will see New shoot tips curl and leaf undersides turn sticky What to do Wash them off with a jet of water, and use an egg-yolk oil spray if it recurs. A line of ants running up the trunk means aphids above
Scale insects You will see Rows of brown scabs along the branches, followed by sooty mould What to do Scrape them off the branches in winter and apply a horticultural mineral oil before bud break in spring

This page describes how a crop is grown and used. It does not claim health effects for any food, nor is it intended to prevent or treat disease. Component and study notes are references only and do not mean the same result occurs in people. Consult a medical professional about health concerns.

Health Benefits

What the Donguibogam records — nature, taste and the origin of the name. The Donguibogam lists this tree in the Wood section as 秦椒 and gives the Korean name as bundi. It describes the nature as warm and the taste as pungent, with some calling it bitter, and records that it has toxicity. The entry explains that fruit from the Qin region is called 秦椒 while fruit out of Sichuan is 蜀椒 or 川椒, notes that the leaves, stems and fruit resemble 蜀椒 but with a shorter taste, finer fruit and a yellow-black colour, and gives the eighth to ninth lunar month as the gathering time. This is a historical medical record and differs from modern medical judgment.

Essential oil composition analyses. Analyses of the essential oil from sancho fruit husks report monoterpenes such as limonene, citronellal and geraniol as principal constituents. The same work reports that the proportions shift with harvest timing and growing region. This concerns aroma composition and has no bearing on preventing or treating disease.

Research on how sanshool-type alkylamides act. Research reports that sanshool-type alkylamides from Zanthoxylum fruit stimulate nerve pathways involved in touch and vibration, producing the buzzing sensation on the tongue. The work notes this is a different pathway from the one behind chilli heat. This concerns a sensory mechanism and does not imply a health benefit.

Nutrition

Essential oil (limonene, citronellal, geraniol) (concentrated in the fruit husk) — the volatile fraction behind the distinctive aroma
Sanshool-type alkylamides (reported across the genus Zanthoxylum) — compounds that leave a tingling sensation on the tongue
Fixed oil (pressed from the black seeds inside the fruit) — the bulk of sancho seed oil

Essential oil in the husk The aroma sits in the fruit husk, not the seed. Analyses report monoterpenes such as limonene, citronellal and geraniol as the main constituents. Because these are volatile, powder ground in advance loses its scent quickly. Keep the fruit whole and grind a little at a time.

The alkylamides behind the tingle Fruits in the genus Zanthoxylum contain alkylamides grouped as sanshools. They are reported to act on touch-sensing nerves rather than the heat pathway, producing a buzzing sensation on the tongue. Sancho carries this less strongly than chopi, which is why chopi dominates as a spice. Content varies widely with the individual tree and how ripe the fruit is.

Fixed oil from the seed Sancho oil is pressed from the black seeds inside the fruit. It is mostly fixed oil, carrying enough husk aroma to smell unmistakable. Pressed oil goes rancid fairly quickly, so keep it in a small bottle somewhere cool. One or two drops finishing a pancake is enough to scent the whole dish.

Pairings

○ Freshwater fish soups — Dusting sancho or chopi powder over strongly flavoured freshwater fish soup is a long-standing habit. The aroma is powerful, so a pinch is the whole dose. Note that packets sold as jepi powder are usually chopi, so read the label.

○ Green fruit pickled in soy or bean paste — Still-green fruit is packed into soy sauce or doenjang as a pickle. Picked before ripening, the aroma is cleaner and the soft seeds are eaten whole. This falls in high summer, about a month before the gathering time given in the old text.

○ As a finishing oil — Sancho oil holds its aroma better drizzled at the end than used as a frying medium. Past a tablespoon the scent takes over the dish.

△ Mistaking it for lacquer tree or Chinese sumac when foraging — Sancho has pinnate leaves, so from a distance it resembles the lacquer tree or Chinese sumac. The reliable difference is the prickles: sancho stems and leaf stalks carry them, the lacquer tree does not. Brushing against a lacquer tree gives some people contact dermatitis. Buy a sapling and plant it rather than gathering from the hills. Lacquer Tree

△ Grinding the black seed in with the husk — The aroma is in the husk; the black seed is bitter and harsh. For powder, shake the seeds out of the split ripe fruit and grind only the husk. Grinding the whole fruit leaves a muddy aftertaste. The Donguibogam itself records this material as 有毒, having toxicity, so do not use large amounts at once.

△ If you are sensitive to spices — A very small amount of sancho leaves a strong aroma and a lingering tingle. Anyone with a delicate stomach or a low tolerance for spices should cut the quantity. Keep it within the range of a seasoning rather than treating it as something taken for health.

Varieties

Seedling-grown local stock (sapling) — Raised from seed. Prickle thickness and fruit set vary a great deal from tree to tree
Low-prickle selections (sapling) — Grafted stock chosen from trees with sparse prickles. Far kinder on the hands at harvest
Confirmed female grafted stock (sapling) — Sancho is dioecious, so only female trees fruit. Buy stock confirmed as female if you want a crop

Source: Donguibogam, Wood Section 秦椒 · Rural Development Administration (Nongsaro) · Korea National Arboretum species database