Thai Herb Pairings: How Thai Aromatic Ingredients Work Together

Thai herb pairings usually fall into four groups. Each group does a different job, and most Thai dishes are built from one or more of them.

• The citrusy trio of lemongrass, galangal and makrut lime leaves gives soups like tom yum and tom kha their fragrance.
• The pounded base of garlic, coriander root and white pepper anchors marinades and curry pastes.
• Holy basil with garlic and chili is the stir-fry pairing behind pad kra pao.
• Soft fresh herbs such as mint, cilantro, culantro and Thai basil go in at the end of salads and curries for brightness.

All of these sit on top of the classic Thai balance of salty, sour, sweet and spicy.

What are the core Thai herb pairings?

The table below summarizes the main Thai aromatic ingredient combinations. It shows what each pairing tastes like and where you are likely to meet it first.

Why do lemongrass, galangal and makrut lime leaves work so well together?

Lemongrass, galangal and makrut lime leaves pair well because each adds a different side of citrus and spice.

• Lemongrass brings a soft lemon perfume.
• Galangal adds a sharp, piney heat.
• Makrut lime leaves contribute an intense, floral lime scent.

Together they make a broth smell layered rather than simply sour. This trio is the aromatic backbone of tom yum (hot and sour soup) and tom kha gai (chicken and galangal soup in coconut milk). It also appears in many curry pastes.

Lemongrass: what it looks like and what it adds

Lemongrass is a long, firm grass stalk. It has a pale, slightly bulbous base and tough, grey-green outer leaves.

• Where the flavor is: Most of the flavor sits in the lower, paler part of the stalk. The upper green part is dry and fibrous.
• How to recognize good stalks: When you cut or bruise a fresh stalk, it releases a clean, lemony smell without the sourness of actual lemon.
• How it is used: Cut into chunks and bruised for soups, or sliced very thinly and pounded into pastes.
• In salads: Paper-thin slices from the tender inner core can be eaten raw.
• Eating the pieces: In soups, large chunks are usually left in the bowl and pushed aside rather than eaten.

Galangal: how it differs from ginger

Galangal is a rhizome related to ginger, but it tastes very different.

• How it looks: Smooth, cream-colored skin marked with darker rings, often with pink tips on young shoots.
• How it feels: Noticeably harder and woodier than ginger when you cut it.
• How it tastes: Ginger is warm and juicy-sweet. Galangal is sharper, with a piney, peppery and almost medicinal citrus note.
• How it is used: Thin coins in soups, or chopped and pounded into curry pastes.

Swapping ginger for galangal will make tom kha taste noticeably different. The dish will be warmer and sweeter, and it will lose its distinctive piney edge.

Makrut lime leaves: how to recognize them

Makrut lime leaves are glossy, dark green leaves that look like two leaves joined end to end. This figure-eight shape comes from a lobed leaf stem.

• Aroma: Crushing one releases a powerful, floral lime smell that is stronger than lime zest.
• In soups: Torn and dropped in whole.
• In stir-fries, fish cakes and salads: The tough central rib is pulled out and the leaf is sliced into hair-thin shreds.
• Zest: The bumpy rind of the makrut lime fruit is also used in some curry pastes.

What is the garlic, coriander root and white pepper paste?

Garlic, coriander root and white pepper form one of the most basic seasoning pastes in Thai cooking. The three are pounded together in a mortar.

• Garlic gives pungency and body.
• White pepper adds a gentle, lingering heat.
• Coriander root contributes a deep, earthy version of cilantro flavor.

The paste is rubbed onto chicken or pork before grilling. It is also fried at the start of soups and stir-fries, and it forms part of the base of many curry pastes.

What is coriander root?

Coriander root is the pale, thin, stringy root of the same plant that produces cilantro leaves. It looks like a small bunch of off-white threads attached to the bottom of the stems.

Its flavor is stronger and earthier than the leaves. It also holds up to cooking and pounding, whereas the leaves fade quickly. Many supermarkets trim the roots off, so look for whole cilantro plants at Asian grocers.

If you cannot find roots, finely chopped cilantro stems are the closest substitute. They carry more flavor than the leaves, but they are milder and greener than the root.

How do Thai basil, holy basil and other fresh herbs differ?

Thai fresh herbs are not interchangeable. Each one has its own aroma and is matched to specific dishes. Some are cooked briefly, while others are added raw at the end so their scent stays bright.

Thai basil

Thai basil (horapha) has smooth, pointed green leaves, purple stems and often purple flower buds.

• Aroma: Sweet and clearly anise- or licorice-like.
• Pairs best with: Rich coconut curries, especially green and red curry.
• How to use it: Stir the leaves in just before serving. They wilt fast and lose aroma if boiled for long.
• Compared with Italian basil: Italian sweet basil is softer, rounder and less anise-forward. It works as a substitute in curries, but the flavor will be milder and less distinctive.

Holy basil

Holy basil (kaphrao) has smaller, slightly fuzzy leaves with serrated edges. Its stems may be green or purplish.

• Aroma: Peppery and clove-like rather than sweet.
• Classic pairing: Garlic and fresh chili in pad kra pao, a fast stir-fry of minced meat served over rice, often with a fried egg.
• How it behaves: Unlike Thai basil, holy basil is meant to be cooked. Heat brings out its spicy fragrance.
• Substitutes: Thai basil is the usual stand-in. The dish will taste sweeter and lose its peppery bite.

Mint

Mint in Thai cooking is used mostly raw, in generous handfuls.

• Where it shines: Warm meat salads such as larb (minced meat salad) and nam tok (grilled meat salad).
• What it pairs with: Lime juice, fish sauce, chili flakes, sliced shallots and toasted rice powder.
• What it adds: A cool contrast to the heat and sourness.
• When to add it: Tear or add whole leaves at the last moment so they stay bright green.

Cilantro and culantro

Cilantro and culantro have a similar flavor but look completely different.

• Cilantro: Delicate, lacy, flat leaves on thin stems. Scattered over soups, noodles and salads as a fresh garnish.
• Culantro (sawtooth coriander): Long, narrow, stiff leaves with saw-toothed edges. Its cilantro-like flavor is noticeably stronger and survives a little more heat.
• How culantro is used: Sliced into larb and nam tok, alongside mint and cilantro.
• Swapping them: Cilantro can replace culantro if you use more of it. The result will be lighter and less punchy.

How do Thai herbs balance salty, sour, sweet and spicy flavors?

Thai herbs rarely stand alone. They are paired with four main seasonings that set the flavor balance of a dish:

• Salty: fish sauce
• Sour: lime juice or tamarind
• Sweet: palm sugar
• Spicy: fresh or dried chilies

The herbs add aroma on top of that balance. Some typical matches:

• Lime juice and makrut lime leaves reinforce each other's citrus notes in tom yum.
• Coconut milk softens galangal's sharpness in tom kha.
• Fish sauce and chili give holy basil something bold to cut through in pad kra pao.
• Fresh mint and cilantro lift the heavy, salty-sour dressing of larb so it does not feel flat.

How do you prepare Thai aromatics at home?

Thai aromatics need either bruising, slicing or pounding to release their oils. The right method depends on whether they will be fished out, eaten, or ground into a paste.

Preparing aromatics for soup

1. Trim off the dry top and the root end of each lemongrass stalk. Peel away one or two tough outer layers.
2. Cut the lemongrass into short lengths. Bash them with the back of a knife or a pestle until they split and smell lemony.
3. Slice galangal into thin coins. Peeling is optional for young, fresh galangal.
4. Tear makrut lime leaves in half, or crush them in your hand, to release their scent.
5. Add all three to simmering broth before the meat or vegetables so the liquid has time to absorb their aroma.

Pounding a paste in a mortar

A Thai granite mortar and pestle is the traditional tool for curry pastes and the garlic, coriander root and pepper base. It is heavy and stone-gray, with a deep bowl. Its weight crushes fibers and releases oils more fully than chopping.

A lighter clay mortar with a wooden pestle is used for som tam (green papaya salad). That dish needs bruising rather than grinding.

1. Start with dry spices such as white peppercorns, and grind them first.
2. Add the hardest, most fibrous ingredients next, such as sliced lemongrass, galangal and coriander root. Pound until broken down.
3. Add softer ingredients like garlic and shallots last, and pound until the mixture becomes a coarse paste.

Adding fresh herbs

1. Add Thai basil to curries off the heat or in the final moment of cooking.
2. Toss holy basil into a stir-fry during the last few seconds over high heat, until just wilted.
3. Fold mint, cilantro and culantro into salads right before serving so they stay crisp.

A food processor can stand in for a mortar. Add a little oil or water to keep the blades moving. The paste will be slightly less fragrant and smoother than a pounded one.

What are good substitutes for Thai herbs, and what are their limits?

Substitutes for Thai herbs can get a dish close, but none reproduce the original aroma exactly. Where possible, frozen fresh aromatics are usually a better choice than dried ones.

Lemongrass, galangal and makrut lime leaves all freeze well. Buying a larger batch at an Asian grocer and freezing it is a practical way to keep them on hand. Delicate leafy herbs such as basil, mint and cilantro do not freeze well for fresh use, so buy those when you plan to cook.

What are common mistakes with Thai herb pairings?

The most common mistakes are treating similar herbs as identical and cooking delicate herbs too long.

• Mixing up the basils: Using Thai basil and holy basil interchangeably changes a dish's character more than most people expect.
• Boiling soft herbs: Long-cooked mint, cilantro or Thai basil turns dark and loses its fragrance.
• Leaving aromatics unbruised: Whole, unbruised lemongrass gives off very little flavor.
• Leaving in the lime leaf rib: If makrut lime leaves are meant to be eaten, remove the central rib, which stays tough even when cooked.
• Overloading one aromatic: Thai aromatic ingredient combinations work through balance. Too much galangal, for example, can make a soup taste harsh and medicinal.

Once you can recognize these herbs by sight and smell, Thai menus start to make sense. Try pairing them with the dishes above, and you will begin to notice the same groupings again and again in Thai cooking.