Galangal is one of the base aromas of Thai cooking — the rhizome behind the clean, citrus-pine lift of tom yum, tom kha and Thai curry pastes. Yellow galangal, kha lueang, is a native Thai variety with pale yellow flesh. Dried and ground, it smells of eucalyptus, lime peel and pine, with a short, peppery bite.
Southeast Asia, from southern China and Indochina to Java and the Philippines; grown throughout Thailand
Flavour profile
Eucalyptus-cool · lime peel and pine · peppery bite · warm wood
Part used / form
Rhizome — sliced, dried and finely ground
Meet the spice
What is galangal?
Galangal is a tall tropical plant of the ginger family, Zingiberaceae. Its leafy stems grow to around 1.5 m, with long, glossy leaves. The part we cook with grows underground: a thick, ringed rhizome — an underground stem, although it is usually sold as “galangal root”.
The rhizome is 3–4 cm thick, creamy white to pale yellow inside, ringed with brown scale-like bands and tipped with pink shoots. Its round fruits ripen from red-orange to black.
Galangal is a relative of ginger, but not ginger. Its aroma is cooler and more resinous, and its bite comes from a different compound (see “The science of flavour”).
Freshly dug yellow galangal rhizomes with ringed skin and fine roots
Young shoots
Cut at about three months, the tender shoots, no kha, are the first harvest — a vegetable in their own right.
Young galangal
Kha on, six to eight months old: tender, juicy and mild. The choice for tom kha.
Mature galangal
Kha kae, a year or older: firmer, more fibrous and stronger. For tom yum and curry pastes.
Curry pastes
Pounded with chillies, lemongrass, shallot and garlic as one of the base aromas of Thai curries.
Fish and meat
Added to marinades, soups and curries to take away strong fishy or gamey smells.
Dried and ground
Sliced, dried and milled — for soups, curries and marinades all year round.
The story
A short history of galangal
Galangal has travelled further than most cooks know. Its name crossed Asia and reached medieval Europe long before tom yum became famous around the world.
Before written records
A rhizome of Southeast Asia
Galangal grows naturally from southern China and Indochina to Java and the Philippines, and has long been planted in kitchen gardens across the region.
The Middle Ages
“Galingale” reaches Europe
Arab and Venetian traders brought a spice called galingale to Europe, where it flavoured spiced wine. Its name came through Persian and Arabic khalanjān, probably from Chinese gāo liáng jiāng. Historians are still not sure which plant those early records meant — greater galangal, lesser galangal or another rhizome.
1797
Named by botanists
Linnaeus first described the plant as Maranta galanga. In 1797 the German botanist Carl Ludwig Willdenow moved it to Alpinia, the name it carries today.
1908
Weighed into Thai curries
Mae Krua Hua Pa, Thailand’s first cookbook, lists galangal by weight in its curry recipes — fresh, scraped white and cut into rounds.
2024
Tom yum kung, world heritage
UNESCO added tom yum kung to its list of the intangible cultural heritage of humanity. Galangal is one of the soup’s core ingredients, with lemongrass, kaffir lime leaves and shallots.
Tom yum kung grew up in the riverside communities of Thailand’s Central Plains, and galangal is the backbone of the soups and curry pastes of Thai cooking. Cooks use it with fish and meat to take away strong smells, and balance it with care: too much makes a curry dry and astringent, too little leaves it without depth.
In the Northeast, galangal goes into herb-rich dishes such as kaeng om, a curry cooked without coconut milk.
From farm to pouch
Grown across Thailand
Galangal is grown all over Thailand — in fields, between fruit trees and in kitchen gardens. It grows as a clump of leafy stems, and Thai growers harvest it at different ages, each with its own use in the kitchen. Growers also speak of red, yellow and white galangal; a Thai study of 22 samples from around the country found that all three were the same species, A. galanga.
Galangal growing between fruit trees
About 3 months
Shoots
Tender young shoots are the first harvest.
6 – 8 months
Young galangal
Juicy and mild, with little fibre.
A year or more
Mature galangal
Firmer and more fibrous, with a stronger aroma.
After harvest
Slicing and drying
Cut galangal darkens in the air. Thai growers keep fresh rhizomes bright in water with alum, and cooks soak slices in water with lime juice. In Thai drying trials, slices dried at 45 °C in dry air kept the most of galangal’s pungent compound; hotter, more humid air browned them and broke more of it down, while drying too slowly also changed the colour.
What to look for
A pale cream to straw-yellow colour, not dull brown
A clear smell of eucalyptus, lime peel and pine when you open the pouch
A clean, peppery bite that fades quickly
No musty, damp or burnt smell
A dry powder that pours freely, without lumps
A little fibre, which is natural in ground rhizome
Fresh yellow galangal: yellow-skinned, ringed rhizomes with stems and roots still attached.
Sun or shade
Galangal is often dried in full sun: it is quick, but the slices can darken. Some growers give the slices only a few hours of sun and then dry them slowly in the shade, under a roof. It takes longer, but the slices stay paler and keep more of their fresh, citrus-pine aroma.
The science of flavour
Why galangal smells of eucalyptus and pine
Galangal’s aroma comes from volatile compounds in the rhizome. Three lead the way in fresh galangal: 1,8-cineole, galangal acetate and myrcene (see “What researchers are exploring now”). Analyses of galangal oil add camphor, methyl cinnamate and fenchyl acetate. Their balance shifts with variety, age, plant part and drying, so every harvest smells slightly different.
1,8-Cineole
Cool and eucalyptus-like. The strongest single contributor to galangal’s aroma, and often the largest part of its essential oil.
Galangal acetate
Galangal’s signature, also called ACA: a cool, woody, ginger-like smell, and the compound behind its peppery bite.
Myrcene
A fresh, slightly resinous note, also found in hops and bay leaves.
Camphor
The cool, woody, sharp edge — a few per cent of the oil.
Methyl cinnamate
A fruity, balsamic note that softens the cool, sharp top of the aroma.
Fenchyl acetate
Pine-like and sweet-herbal. Far richer in the fine roots than in the rhizome, so roots in the powder change its aroma.
Why galangal bites
A different receptor: Chilli heat works through the TRPV1 receptor. Galangal acetate leaves it alone and acts on TRPA1 — the receptor behind the bite of mustard and wasabi.
Short and clean: The bite builds fast and fades quickly, without the lingering burn of chilli.
Fragile in heat and water: Galangal acetate breaks down in long cooking. It is missing altogether from steam-distilled galangal oil.
Fresh galangal smells purer and greener. Dried and ground, it is less fresh but more spicy — somewhere between ginger and cinnamon, as one spice writer puts it. The powder is not a copy of the fresh rhizome but a spice of its own: warmer, drier and easy to measure.
In the kitchen
Cooking with yellow galangal
Eucalyptus
Cool on the nose
Citrus-pine
The bright middle
Peppery bite
Short and clean
Warm wood
A dry, resinous finish
Ground yellow galangal
Ways to use it
Tom yum, tom kha and other soups
Thai curry pastes
Vegetable stews and curries
Marinades for meat and fish
Stir-fries and fried rice
Fish and seafood dishes
Spiced wine — a newer pairing, not Thai tradition
Roast vegetables — a newer pairing, not Thai tradition
Fish and mussel soups — a newer pairing, not Thai tradition
Meat and stews — a newer pairing, not Thai tradition
Aroma compounds from published analyses; character notes are general culinary descriptions, not measurements. The lesser-galangal entry refers to fresh and dried Vietnamese rhizome oils analysed by Ly, Yamauchi & Kato (2001); composition varies with the material and preparation.
Galangal is first of all a spice. In Thailand it also has a long place in traditional medicine, and its compounds interest researchers today.
Traditional use
Thai traditional medicine describes the mature rhizome as hot and pungent, used to “expel wind” — for bloating and a heavy stomach — and on the skin for fungal rashes. Hildegard of Bingen recommended “galgant” for heartburn, probably meaning lesser galangal. These are traditional uses, not proven treatments.
In the laboratory
Galangal acetate and galangal extracts have been studied in cells and in animals for a wide range of effects. These studies use concentrated extracts or the pure compound, not a pinch of spice, and do not show what eating galangal does in people.
A trial with 128 habitual caffeine users in its acute stage and 127 in its 28-day stage compared a 300 mg branded galangal extract, caffeine, both and placebo. Some attention measures differed from placebo at selected times. Several authors were affiliated with the extract maker. This does not test ordinary galangal powder in food.
Sniffing the separated compounds of fresh galangal one by one, researchers in Germany found 43 odour-active compounds, 18 of them new to the plant. Just 20 of them, mixed in their natural amounts, recreated the galangal aroma.
