What's Different About Makrut Lime Leaves?

Makrut lime leaves are the glossy double leaves of a Southeast Asian citrus tree, used for a floral citrus perfume with almost no sourness. The way they are cut decides whether anyone eats them. Torn whole leaves infuse soups and curries and stay on the side of the bowl, while deveined hair-thin shreds soften into the dish.

Are makrut lime leaves the same as kaffir lime leaves?

Both names describe the leaves of one thorny citrus tree, Citrus hystrix, native to tropical Southeast Asia. Makrut is the Thai name, and a Thai recipe calls the leaf bai makrut.

Shops in the West may also label it Thai lime leaf, and Malaysian and Indonesian recipes know the same tree as limau purut or jeruk purut.

Kaffir is the older English name, and it still appears on many packets and in older cookbooks. The same word is a racial slur in South Africa, so many Thai cooks writing in English, food publishers and some supermarkets now use makrut instead.

The citrus name turns up in Sri Lankan records from the late 1800s, and its exact origin is still debated.

Plant

Citrus hystrix, a thorny citrus tree

Native range

Tropical Southeast Asia

Parts used

The double leaf, and the rind of the knobbly fruit

Thai name

Bai makrut for the leaf

Other names

Kaffir lime, Thai lime, limau purut, jeruk purut, combava

Main aroma compound

Citronellal, usually the largest part of the leaf oil

This page uses makrut, and a label with either name means the same leaf.

The leaf is easy to recognize because it looks like two glossy leaves joined end to end. Botanically, the lower half is a flattened, winged leaf stalk and the upper half is the true blade.

Fresh leaves are deep green, stiff and slightly leathery, and a torn edge smells of floral citrus within seconds. Leaves from a Persian lime or lemon tree lack both the joined shape and that strong perfume, so they cannot stand in for makrut.

What do makrut lime leaves taste like?

A torn leaf smells sharply of citrus peel and flowers, with a green note close to citronella grass.

Most of that perfume comes from citronellal, which often makes up the largest share of the leaf's essential oil.

That balance is not fixed from tree to tree. One 2021 analysis found leaf oil that was 78 percent citronellal, while earlier studies of trees from other regions reported anywhere from under 2 percent to about 72 percent.

Some leaf oils in those studies were led by limonene instead. Two bags of leaves can therefore smell noticeably different, so the first torn leaf is a better guide than the count printed in a recipe.

The leaf adds aroma and almost no sourness, which means it cannot replace lime juice when a soup or salad needs acid.

Tearing, bruising or slicing breaks the tiny oil glands in the leaf. Heat then carries the released oil through broth, coconut milk or frying fat.

The flavor sits naturally beside fresh galangal, bruised lemongrass, chiles, garlic, fish sauce, coconut milk, seafood and chicken, the group at the center of the Thai spice pantry.

Because the aroma is so strong, one or two leaves still stand out against fish sauce and shrimp paste. Gray-brown dried leaves with little smell add texture before they add aroma.

Can you eat makrut lime leaves?

You can, but a whole leaf is too tough and papery to chew comfortably. In soups such as tom yum the torn pieces work like bay leaves, flavoring the broth and then staying in the bowl.

Thai cooks often leave them in and diners set them aside, so a leaf in the bowl is normal rather than a mistake.

Fine shreds are a different matter. Once the center vein is removed and the leaf is cut hair-thin, it softens into a curry, a salad or fish cakes and gets eaten with the rest of the dish.

Raw leaf is eaten too when it is cut that fine. Balinese sambal matah is a raw relish of sliced shallot, chile and thin makrut threads, sometimes finished with hot coconut oil poured over the bowl.

The raw threads work there because they are too thin to feel leathery.

Longer simmering will not rescue a wide strip, because the vein stays tough while the aroma fades.

How do you tear, devein and slice makrut lime leaves?

The right cut depends on whether the leaf will be removed or eaten. Large torn pieces are for infusing a liquid, and deveined hair-thin shreds are for anything that stays in the bite.

Dry leaves cut more cleanly than wet ones, because water makes a stack slide under the knife.

1. SeparatePull the two halves of the double leaf apart at the joint.
2. DeveinFold each half along its center vein, glossy side in, and pull the leaf away from the vein from tip to base.
3. Stack and rollStack three or four deveined halves and roll them into a tight cylinder.
4. SliceCut across the roll with a sharp knife into threads about 1 millimeter wide.

For a soup or curry where diners eat around the leaf, tearing is enough. Twisting the leaf once before tearing bruises it and opens more oil glands, and a thin young vein can stay in.

Frozen leaves slice best while they are still firm. Surface ice spatters in hot oil, so a frozen leaf needs patting dry before it is fried.

How are makrut lime leaves used in soup, curry and stir-fry?

Timing and cut change with the dish, because the leaf gives up its aroma quickly and loses it under long, hard cooking.

The loss has a simple cause. Laboratories collect makrut leaf oil by boiling the leaves in water for hours and catching what rises with the steam, so an open, rolling pot sends the same oil into the kitchen air.

Torn leaves go into tom yum, tom kha and other coconut soups early, together with the lemongrass and galangal, so their oil has time to spread through the broth. The pieces are then left in or lifted out at the table rather than chopped fine.

Curries often use the leaf twice, with torn leaves simmered in the sauce and a pinch of fine shreds added at the end for a fresher top note.

Panang, a thick and rich red curry, is usually served under a heap of julienned leaf.

Thai fish cakes, tod mun pla, take finely minced or shredded leaf in the fish paste itself. The leaf is deveined first because stringy fibers would wrap around the pestle instead of spreading through the paste.

In a stir-fry the leaf goes in near the end, in line with the usual timing for fresh aromatics. Longer frying leaves it dull and papery.

Dry whole leaves turn crisp after only a few seconds of frying in hot oil, and they scorch soon after that.

Where are makrut lime leaves used beyond Thai cooking?

Indonesian, Malaysian, Cambodian and Lao cooks use the leaf too, and so do cooks on the Indian Ocean island of Réunion.

They keep the same basic rule, torn for broth and cut fine for anything eaten, but some dishes push the leaf much further than a Thai soup does.

Beef rendang from Indonesia and Malaysia breaks the short-cooking habit. One recipe stirs four large, very finely sliced leaves into 1 kilogram of beef, then simmers it covered for over an hour and reduces it uncovered for another half hour.

The shreds are eaten with the meat, because they were cut fine enough to soften.

What survives that long braise is a softer, deeper citrus note than the bright top note of a quick soup.

Cambodian kroeung, the pounded herb paste behind many Khmer dishes, traditionally uses both makrut rind and deveined leaf. Cambodians living abroad often replace the sun-dried rind with extra leaves because the fruit is hard to find outside the region.

On Réunion the tree is called combava, and its rind is considered essential in rougail tomate, the fresh tomato relish served with curries. Leaves and powder also go into rhum arrangé, the island's rum infused with fruit and spices.

Sweet cooking uses the leaf the same way a soup does.

One panna cotta recipe simmers five shredded leaves in 200 milliliters of milk for 5 minutes, then lets them steep off the heat for 30 minutes before straining.

A warm sugar syrup picks up the aroma just as easily, and leaf syrup turns up in lemonade, iced tea and gin gimlets. In desserts and drinks the leaf is strained out, because a torn leaf is as tough in custard as it is in broth.

When does a recipe want the leaf, the rind or the juice?

The makrut tree gives cooks three parts, and each does a different job. The leaf infuses liquids, the grated rind disappears into pastes, and the juice is rarely used in cooking.

The knobbly green rind is a standard part of Thai green and red curry pastes, because finely grated zest pounds smooth where a leathery leaf would stay stringy.

Only the green outer skin goes into the mortar. The white pith underneath is bitter and adds no aroma.

Leaf and rind also smell different, because their oils are built from different compounds. In the same 2021 analysis the leaf oil was mostly citronellal, while the rind oil was led by beta-pinene, with limonene and sabinene close behind.

That split gives the rind a sharper, more pine-like peel note than the floral leaf.

Grated rind and torn leaf therefore work best as partners in a curry rather than as swaps.

The juice is sour and bitter, so Thai cooks reach for ordinary lime when a dish needs acid. In Thailand the juice is better known as a traditional shampoo and household cleaner.

A recipe that simply says makrut lime usually means the leaf when the dish is simmered and the rind when the paste is pounded.

Should you buy fresh, frozen or dried makrut lime leaves?

Fresh leaves have the brightest aroma and the only texture that slices into clean threads.

Frozen leaves come close, keeping most of their aroma although they thaw a little less glossy. They are the practical backup when a Southeast Asian grocer or an online spice shop sells them in freezer packs.

Dried leaves lose much of their volatile oil and taste muted. They stay brittle, so they suit long soups and curries where they have time to soften.

Brittle dried leaf cannot be cut into edible shreds for a salad or stir-fry.

Good fresh leaves are glossy, deep green and firm, and they smell strongly after a gentle rub. Yellow patches, slime or dry, curling edges mean the bundle is past its best.

In the United States, fresh leaves are harder to find than most herbs because of plant-health rules. Citrus greening, a bacterial disease spread by a tiny insect called the Asian citrus psyllid, is found throughout Florida and Georgia and in parts of California, Texas and other states.

Moving citrus leaves out of quarantined areas is restricted. Since 2015, USDA has allowed fresh leaves meant for eating to leave those areas only after cleaning and inspection steps that remove the insect.

That extra handling helps explain why fresh bundles can be scarce or costly, and why the freezer case is often the easier place to look.

How many makrut lime leaves should you use?

Leaves vary in size, so recipe counts are approximate. Published tom yum recipes use five or six leaves, whether the pot serves two or four.

A four-serving soup or curry can start with four to six fresh or frozen leaves, with one more added after 10 minutes if the aroma is faint.

Dried leaves need about twice the fresh count to make up for the aroma lost in drying. They also need the whole simmer to soften and release it.

More leaves will not bring back aroma lost to a long boil. One fresh leaf added late helps more than a handful at the start.

What can you substitute for makrut lime leaves?

Nothing copies the leaf exactly, because its floral green perfume comes from a mix of compounds that lime zest and bay leaf only partly share. The closest swaps are other forms of makrut, then pairs that rebuild the citrus and the green note separately.

A bay leaf supplies the woody infusion that lime zest lacks, which suits the pair to slow coconut curries.

Leaves from a Persian lime or lemon tree carry only a faint citrus smell. A cook with a regular lime tree gets more from a strip of its zest than from a handful of its leaves.

Lime juice is missing from the list because it adds sourness rather than the leaf's aroma. The kaffir lime leaf substitutes guide matches each swap to a specific dish.

How do you store and freeze makrut lime leaves?

Refrigerated leaves keep best dry and sealed, wrapped loosely in a paper towel that soaks up condensation.

Freezing suits any leaves that will not be used soon, because they stay firm and keep most of their aroma. They can go from the freezer straight into a pot or onto the board.

Damp leaves freeze together into one block. Dry leaves laid flat stay separate, so a single leaf can come out without thawing the rest.

• Dry firstPat every leaf dry before it goes into the refrigerator or freezer.
• Freeze flatSpread the leaves on a plate until firm, then bag them.
• Press out airA flat, airless bag protects the leaves from freezer burn.
• DiscardSlimy, moldy or sour-smelling leaves go in the bin.

Dried leaves and powder follow the same rules as other dried spices in storage, and their aroma fades faster than that of fresh or frozen leaves.