spice guide
Zanthoxylum myriacanthum
Makhwaen is the aromatic spice of Northern Thailand’s hills — the dried fruit of a thorny tree in the citrus family. Toasted and crushed, it smells of lime peel and pine, with warm wood underneath and a light tingle on the tongue. In the North it is the signature aroma of laab and many northern curries.
Meet the spice
Makhwaen is the fruit of a thorny tree of the citrus family, Rutaceae. It shares its genus, Zanthoxylum, with Sichuan pepper, but it is not a true pepper: black and white pepper come from a climbing vine, Piper nigrum.
The trees carry large, loose clusters of tiny round fruits, each 2–3 mm across. They ripen from green to reddish brown, then dry and split open like a small star around a glossy black seed. Most of the aroma sits in the husk; the seed is hard and gritty.
Trees are either male or female. Only female trees bear fruit, usually from three to five years after planting.
The form that keeps best, toasted and crushed just before cooking — and how we sell it.
Phrik laab, the dry spice mix for northern laab, where makhwaen is one of the key aromatics.
Gaeng khae, a northern curry of vegetables and herbs, and spicy yam salads.
Pounded into nam phrik, the northern chilli dips eaten with vegetables.
In season, pickled in fish sauce and eaten alongside laab.
The tender young leaves are eaten fresh, dipped into chilli relishes.
The story
Makhwaen has no single written origin story. Its history lives in northern Thai kitchens and hill communities — and, more recently, in botany and research.
People in the hills of what is now Northern Thailand and Laos took makhwaen from forest trees for their chilli pastes and meat dishes. On Doi Phu Kha in Nan, the Lua people still count it among their important food plants.
In the kingdoms of the North, laab became a dish for celebrations and guests — its name sounds like the Thai word for good fortune. Locally grown makhwaen joined spices brought in by traders, such as cloves, nutmeg and star anise, in the phrik laab blend.
The trees behind makhwaen received their scientific names: Z. rhetsa in 1824, and Z. myriacanthum in 1875 in Joseph Hooker’s Flora of British India, based on a name given earlier by the botanist Nathaniel Wallich.
Thai researchers analysed makhwaen from Nan and the North: its essential oil (2015), the best harvest time for aroma (2019) and, using DNA, its species (2021).
Makhwaen is still grown on small farms and in the forests of Nan and its neighbouring provinces. Outside Thailand it remains a rarity, found mainly in specialist spice shops.
Northern laab is a different dish from the lime-sharp laab of the Northeast. Laab muang, the northern version, uses no lime juice: its flavour comes from phrik laab, a dry blend of roasted spices.
In the west of the old Lanna region the blend can hold more than ten spices. In the east — Nan and Phrae — it is simpler, and makhwaen leads with its cool, peppery tingle. Cooks also value it for taking away the gamey smell of meat.
From tree to pouch
Nan is a mountainous province of Northern Thailand on the border with Laos. Makhwaen grows there in cool, humid hill country — in forest and on farms, often among fruit trees. It likes full sun and rich, loamy soil, and in natural forest it grows at around 800–1,000 m.
Female trees flower in the middle of the rainy season — early types in July, later ones in August.
The fruit ripens from green to reddish brown. Early types are picked in October and November, later types in November and December.
In one study, citrus and pine notes were strongest in fruit picked about 45 days after fruiting; younger fruit smelled sweeter and woodier.
The clusters are tied into bundles and dried in the sun for three to four days, and taken indoors at night so dew cannot cause mould. As they dry, the husks split open around the black seeds.
Aroma is fragile. Thai researchers have compared harvest times and drying methods for makhwaen and found clear differences in its aromatic profile.
The science of flavour
Makhwaen’s aroma comes from its essential oil, which makes up several per cent of the dried fruit. The oil is made up mostly of monoterpenes, the family of compounds that scents citrus peel, pine needles and many herbs. Their balance shifts with species, place, ripeness and drying, so every harvest smells slightly different.
The bright citrus note, also found in lemon and orange peel — often the largest single compound in makhwaen oil.
Woody, spicy and gently citrus. Researchers use it, together with limonene, as a marker of good makhwaen aroma.
α- and β-phellandrene add a fresh, slightly minty lift to the citrus.
α- and β-pinene bring the evergreen, pine-needle note. In one extract of makhwaen from Nan, β-pinene was the main compound.
A warm, spicy note with a slightly cool edge, present in smaller amounts — around 6–11 % in Thai samples.
Not part of the smell but of the feeling: the alkylamides behind the tingle of Zanthoxylum spices. As far as we know, they have not yet been measured in makhwaen itself.
The tingle of Zanthoxylum spices is not heat. Capsaicin in chilli and piperine in black pepper act on pain and heat receptors; sanshools work through the sense of touch.
In the kitchen
Makhwaen Whole Peppercorns — 25 g to 50 g ↗
Makhwaen recipes and pairings in the Journal →
| Spice | Species · origin | Main aroma compounds | Character |
|---|---|---|---|
| Makhwaen | Z. myriacanthum and relatives · Northern Thailand | Limonene, sabinene | Lime peel, pine and warm wood; light tingle |
| Sichuan pepper | Z. bungeanum · China | Linalool, limonene | Floral, woody citrus; strong, numbing tingle |
| Timur | Z. armatum · Nepal | Linalool, limonene | Floral, grapefruit-like citrus; clear tingle |
| Sansho | Z. piperitum · Japan | Limonene, β-phellandrene, citronellal | Lemon peel with a minty, floral edge; lively tingle |
Aroma compounds from published analyses; character notes are general culinary descriptions, not measurements.
Beyond flavour
Makhwaen is first of all a spice. In the North it has also long had a place in folk medicine, and its compounds interest researchers today.
Different parts of the tree were used in home remedies: the leaves were pressed onto an aching tooth, and the seeds, roots and wood went into remedies for wind and dizziness. These are traditional uses, not proven treatments.
In test-tube studies, essential oils and extracts of makhwaen from Northern Thailand — including one from Nan — showed antioxidant and antimicrobial activity. These studies use concentrated oils, not a pinch of spice, and do not show what eating makhwaen does.
Food Research International · 2020
Human sensory studyIn a sensory study with 68 tasters, Sichuan pepper extract increased perceived saltiness in salt solutions. This concerned a related spice, not makhwaen, and was not a test of meals or health outcomes.
Open resource ↗Plants · 2021
Botany & aromaDNA markers identified northern Thai makhwaen as Z. myriacanthum, a species often confused with Z. limonella. Its essential oil had fruity, woody and citrus notes, while related hua jiao was more floral.
Open resource ↗Educational product information. Not medical advice.
From our journal
A guide to the names on European spice shelves, the differences that matter and the citrus-and-pine character of our Northern Thai Makhwaen.
