10 Thai kitchen herbs: which part to use, look-alikes, and buying fresh
Lemongrass, galangal, makrut leaf, holy basil, Thai basil, fingerroot, turmeric, bird's eye chili, pandan and culantro: what to use, how they taste, how to pick them.
- Thai kitchen herbs use different parts - some the leaves, some the rhizome, some the base of the stalk.
- Holy basil, Thai basil and lemon basil are easiest to tell apart by smell - peppery-hot, sweet anise, and lemony.
- Galangal, ginger and fingerroot differ in rhizome shape and flesh colour; turmeric flesh is deep orange and stains your hands.
- Fresh herbs are firm, not wilted, unbruised, and release their smell the moment you snap or crush them.
Thai cooking uses fresh herbs at almost every meal, and many of them look alike - holy basil and Thai basil, galangal and ginger - so the wrong one ends up in the basket all the time. This is the first lesson of the path “Thai herbs in the kitchen”: the ten herbs used most often, which part you use, what they taste like, which dishes they go into, how to tell each from its look-alikes, and how to spot fresh ones at the market.
This lesson treats herbs purely as cooking ingredients. Taking them as medicine, and where food ends and medicine begins, is covered in lesson three.
The ten at a glance
| Herb | Part used | Smell and taste | Where you’ll meet it |
|---|---|---|---|
| Lemongrass | white base of the stalk | lemony, fresh | tom yum, salads, curry paste |
| Galangal | rhizome | sharp, piney, peppery | tom kha, tom yum, curry paste |
| Makrut lime leaf | leaves, fruit zest | strong, fresh citrus | tom yum, red curry, fish cakes |
| Holy basil (kaprao) | leaves, tips | peppery, hot | pad kaprao, pad cha, jungle curry |
| Thai sweet basil (horapha) | leaves, tips | sweet, anise-like | green curry, red curry, eaten raw with larb |
| Fingerroot (krachai) | finger-shaped rhizomes | distinctive, lightly peppery | jungle curry, khanom chin nam ya, kaeng liang |
| Turmeric (khamin) | rhizome | earthy, slightly bitter, colours yellow | southern yellow curry, kaeng tai pla, turmeric fried chicken |
| Bird’s eye chili | fruit | very hot | nam pla prik, som tam, chili dips |
| Pandan | leaves | soft, sweet | desserts, pandan drink, chicken wrapped in pandan |
| Culantro | leaves | like coriander but much stronger | tom yum, larb, nam tok |
Lemongrass, galangal, makrut: the tom yum trio
Lemongrass (ตะไคร้, takhrai): use the base of the stalk, the part that is white to pale purple. Peel off the tough outer layers, then slice or bruise it so the scent comes out. The leaves are too tough to eat but can be boiled for a drink. Fresh lemongrass is firm and heavy with a plump base, and smells strongly when you snap or squeeze it. A shrivelled base, dry wrinkled skin or very dry yellow tips mean it has been sitting around.
Galangal (ข่า, kha): the rhizome is denser and harder than ginger, with a sharp, piney heat that is quite different from ginger’s. Young galangal has creamy-pink skin, pink shoots and tender flesh, good sliced thin into tom kha. Older galangal has darker skin and hard, fibrous flesh, better pounded into curry paste. Pick rhizomes with tight skin and no bruises or mould.
Makrut lime leaf (ใบมะกรูด, bai makrut), often sold as kaffir lime leaf: thick, glossy, and shaped like two leaves joined with a pinch in the middle. Tear it and pull out the central rib before it goes in the pot. The zest of the knobbly fruit goes into curry paste. Fresh leaves are deep green, not yellow, and smell strong when crushed. Skip any that are yellowing or spotted black.
Holy basil, Thai basil, lemon basil: telling them apart
All three belong to the same genus and look very alike. The most reliable test is to crush a leaf and smell it.
| Holy basil (กะเพรา) | Thai sweet basil (โหระพา) | Lemon basil (แมงลัก) | |
|---|---|---|---|
| Smell | peppery, hot | sweet, anise-like | lemony |
| Stem | soft short hairs, green or purple | usually purple, smooth | green |
| Leaves | small, toothed, matte, slightly hairy | larger, smooth, glossy | pale green, thinner than Thai basil |
| Flowers | white or pale lavender | purple spikes | white |
| Used in | pad kaprao, pad cha, jungle curry | green and red curry, eaten raw | kaeng liang, khanom chin |
Holy basil comes in a “white” type with green stems and leaves and a “red” type tinged purple. The red type often smells stronger; both are used the same way.
When buying, look for leaves that stand up, aren’t wilted or black-spotted, and haven’t been squashed in a tight bunch. All three bruise and darken quickly, so buy only what you’ll use in a day or two.
Galangal, ginger, fingerroot, turmeric: look at the rhizome
These four are in the same family and easy to mix up in a market basket.
- Galangal: large, plump rhizome with clear ring-like joints, cream to pale pink skin, ivory, hard flesh.
- Ginger: thin light-brown skin, pale yellow flesh, hot and pungent, without galangal’s pink shoots.
- Fingerroot: the easiest to spot. A cluster of slender “fingers” about 6-10 cm long grows from a small central knob, like a hand. Light brown skin, yellow flesh inside.
- Turmeric: brownish-orange skin. Snap it and the flesh is deep orange to orange-yellow, and it stains your fingers yellow. Watch your chopping board and clothes.
Thai markets also sell white turmeric (ขมิ้นขาว, khamin khao), with pale cream-yellow flesh. It doesn’t colour food like turmeric and is usually sliced and eaten raw with chili dips. If you want a yellow curry, snap the rhizome and check the colour before you buy.
Fresh rhizomes are firm and heavy for their size, with tight, unwrinkled skin, no white mould at the joints, and no soft, sunken spots.
Bird’s eye chili, pandan, culantro
Bird’s eye chili (พริกขี้หนู, prik khi nu): the fruit is used green or red. The tiny garden type (prik khi nu suan) is fiercely hot and fragrant; the larger, longer types are milder. Choose chilies with tight, shiny skin, green fresh stems, and no bruises or black spots. If you are chopping a lot, wear gloves and keep your hands away from your eyes.
Pandan (ใบเตย, bai toei): long strap-like leaves with a soft, sweet scent, used in desserts, boiled drinks, rice, and wrapped around fried chicken. Fresh leaves are deep green, not badly torn, and release their scent when bent. Leaves that are yellow or dry at the tips have lost much of their aroma.
Culantro (ผักชีฝรั่ง, phak chi farang): not the same as coriander. Culantro has long, narrow, single leaves with small spiny teeth along the edge, growing in a rosette from the base. It smells like coriander, only much stronger. It goes into tom yum, larb and nam tok, and is eaten raw on the side. Choose leaves that are deep green and stiff, not limp or yellowing.
Example: shopping for one pot of tom yum
Say you are making tom yum for four. These are typical home amounts; adjust to taste.
- Lemongrass: 2-3 stalks, base only, outer 1-2 layers peeled off
- Galangal: 5-8 thin slices, from a thumb-length piece
- Makrut lime leaves: 4-6, torn, centre rib removed
- Bird’s eye chilies: 5-10, depending on how hot you like it
- Culantro: 2-3 leaves, sliced in at the end
Lemongrass, galangal and makrut leaves aren’t meant to be chewed - most people lift them out or eat around them - so cut them into big pieces that are easy to pick out.
Crush the leaf, snap the rhizome, and smell it. That is the best way to tell look-alike herbs apart, and it checks freshness at the same time.
Common mistakes
- Using Thai basil for pad kaprao. It’s tasty, but it’s a different dish. For the real smell, you need holy basil.
- Buying ginger instead of galangal. Tom kha comes out with ginger’s heat and the wrong aroma.
- Adding holy basil or Thai basil too early. Add these tender leaves as you turn off the heat, or just before, so the scent survives.
- Slicing lemongrass with its outer layers on. They are tough and stringy; peel them first.
The next lesson grows these herbs in pots and small beds at home, without synthetic pesticides.
Sources
FAQ
How are makrut lime leaves different from ordinary lime leaves?
A makrut leaf looks like two leaves joined end to end with a pinch in the middle, and it is thick, glossy and strongly scented. A lime leaf is a single blade, thinner, with a much milder smell. They do not give the same result in tom yum.
Can I swap culantro for coriander (cilantro)?
In some dishes, but the smell is different. Culantro has long leaves with tiny spiny teeth along the edge, a much stronger smell than coriander, and holds up better in a simmering tom yum. Coriander has smaller, rounded leaves and usually goes on at the end.
I bought too much. How do I keep it?
Tender leaves such as holy basil and Thai basil bruise and darken quickly, so buy only what you will use in a day or two. Rhizomes such as galangal, turmeric and fingerroot, as well as lemongrass and makrut leaves, keep much longer if stored dry and unbruised.
General information, not medical advice. If you are pregnant, take regular medication, or have a liver or kidney condition, ask a doctor or pharmacist before taking herbs beyond normal food amounts.