Makrut lime is a thorny citrus tree of tropical Asia. Its leaf looks like two leaves joined end to end, and its small fruit has a thick, bumpy peel. The leaves scent Thai soups and curries; the peel is pounded into curry pastes. Both are intensely citrus, but in different ways: the leaf sharp and lemony, the peel zesty, piney and faintly bitter.
Scientific name
Citrus hystrix DC.
Family
Rutaceae (citrus family)
Other names
Thai มะกรูด (makrut); jeruk purut (Indonesian); limau purut (Malay); often sold as “kaffir lime”
Origin
Tropical Asia, from the eastern Himalayas to southern China, Indochina and the islands of Southeast Asia; grown in gardens across Thailand
Leaves, fresh or dried; peel, as fresh zest or dried and ground; a little juice
Meet the spice
What is makrut lime?
Makrut lime, Citrus hystrix, is a small, thorny tree of the citrus family. Its name hystrix is Latin for porcupine, after its sharp spines. It belongs to the Papeda group — the sour, bitter-fruited relatives of the familiar oranges and limes.
The leaf is the plant’s signature. Its stalk is winged and almost as large as the blade, so each leaf looks like two leaves joined end to end. Crushed between the fingers, it smells intensely of citrus.
The fruit is small, 5–7 cm long, with a thick, deeply wrinkled peel that turns yellow when ripe. Its flesh is very sour, slightly bitter and gives little juice. For the cook, the treasures are the leaves and the peel.
Fruits on the tree: small, with a thick, wrinkled peelThe “double” leaf: a winged stalk almost as large as the blade
How makrut lime is used
Torn leaves
Bruised, torn and simmered in soups and curries to scent the broth — not meant to be eaten.
Shredded leaves
Cut hair-thin and eaten in salads, stir-fries and fish cakes, or scattered over a curry.
Fried leaves
Fried until crisp as a fragrant garnish.
Peel in pastes
The green zest pounded into red, green and sour curry pastes.
Dried leaves
Whole leaves dried for soups and curries all year round.
Dried, ground peel
The zest in a jar, ready for pastes, marinades and rubs.
The story
A short history of makrut lime
Makrut lime was never a spice of world trade. Its story is told in Thai homes and cookbooks — and, more recently, in a debate about its English name.
Long tradition
Hair, home and blessings
Before shampoo, Thai women rinsed their hair with makrut: the fruit was roasted over the fire, squeezed into water and used for dark, shiny hair. The juice cleaned grease and fishy smells from dishes, and fruits and leaves went into the water of bathing rituals and blessings.
1888
A troubled name
The English name “Caffre-lime” appears in a book on the citrus of India and Ceylon. Where it came from is uncertain.
Early 1900s
In Thailand’s first cookbook
Mae Krua Hua Pa asks for one teaspoon of finely cut makrut peel in its red curry paste, and for shredded leaves over chu chee curry.
2021
A new name in the shops
A large British supermarket renamed its “kaffir lime leaves” “makrut lime leaves”, because in South Africa “kaffir” is a racial slur. Cooks and food writers increasingly use the Thai name.
Today
A farm crop
Besides the tree by the house, Thailand now has makrut farms — some grown only for leaves, others for fruit, peel and the oil used in soaps and shampoos.
Place and food culture
In Thailand, torn leaves scent tom yum and tom kha, and shredded leaves top chu chee curry and fish cakes, tod man pla. The peel goes into red, green and sour curry pastes and into kaeng pa, the jungle curry.
In Cambodia, leaf and peel are pounded into kroeung, the spice paste at the heart of Khmer cooking, and whole fruits are candied. In Indonesia and Malaysia the leaves, daun jeruk purut, season soto ayam and many chicken and fish dishes.
From tree to pouch
Leaf trees and fruit trees
Makrut lime grows in gardens across tropical Asia. In Thailand it is also a farm crop, grown in two quite different ways — trees kept for their leaves need the opposite care to trees kept for their fruit.
A young makrut lime tree
Leaf orchards
Cut back, again and again
Trees are planted about half a metre apart and their leafy branches are cut at 60–80 cm. The first harvest comes four to six months after planting, and the trees keep sending out new shoots.
Fruit orchards
Room to flower
Trees stand at least a metre apart and are left to flower. It takes about four and a half months from flower to fruit; the main season is September to October.
After harvest
Leaves and peel
Leaves are sold fresh or dried whole. For ground peel, the peel is cut from the fruit, dried and milled.
Dried slowly, out of the sun
Leaf and peel owe their scent to volatile oils, and heat drives them off. Studies on makrut leaves found that slow, low-temperature drying kept more colour and aroma than fast, hot drying.
Grinding costs aroma too: in two Indonesian studies, drying and milling the leaves lowered their oil and its key compound, citronellal. Whole dried leaves keep more than leaf powder.
The science of flavour
Two scents from one tree
Makrut lime is unusual among citrus: its leaf and its peel smell clearly different. The leaf oil is dominated by a single compound, citronellal, which makes up roughly 55–80 % of it. The peel oil is a blend, led by β-pinene with limonene and sabinene — and the peel holds more oil than the leaf.
Leaf
Citronellal
The signature of the leaf: sharp, lemony and green. In makrut it is mostly the mirror-image form of the citronellal in citronella grass.
Citronellol
Softer and rosy-citrus. Its share rises when the leaves are simmered in water.
Citronellyl acetate
A fresh, fruity ester that rounds out the leaf’s scent.
Peel
β-Pinene
The lead compound of the peel — fresh, woody and pine-like.
Limonene
The familiar orange-zest note. Makrut peel has much less of it than most citrus peels.
Sabinene
Woody and peppery-fresh; often a fifth of the peel oil.
Cooking changes the leaf
Fried or toasted
In dry heat, citronellal stays in front: the leaves taste sharply citrus.
Simmered
In boiling water, the share of citronellal falls and citronellol rises: the scent turns rounder and softer.
Ground
Milling dried leaves lowers their oil, so whole leaves keep more aroma than leaf powder.
Leaf and peel at a glance
Leaf
Peel
Lead compound
Citronellal, roughly 55–80 % of the oil
β-Pinene, with limonene and sabinene
Character
Sharp, lemony, green and floral
Zesty, piney, faintly bitter
In the kitchen
Cooking with makrut lime
Sharp lemon
The leaf’s first note
Green and floral
Fresh, never sweet
Zest and pine
The peel’s character
Bitter edge
Peel, if overdone
Dried leaves
Bruise and tear. Twist each leaf, tear it into pieces and pull out the tough central rib.
Simmer them in. About six leaves scent a soup or curry for four. Add them with the other aromatics and let them simmer.
Leave them on the plate. Large pieces are for scent only — they are too tough to eat.
Ground peel
Start small. A pinch to ¼ teaspoon for a dish for four.
Cook it in. Add it to a curry paste or hot oil with the other aromatics for depth, or a pinch at the end for a brighter note.
Don’t overdo it. Too much peel turns a dish bitter. Taste, then add.
Ways to use them
Soups
Leaves in tom yum, tom kha and clear broths.
Curries
Leaves in the pot; peel in red, green and jungle curry pastes.
Stir-fries
Shredded leaves with chilli and holy basil; fish cakes.
Marinades and rubs
Ground peel with garlic and pepper for chicken, pork or fish.
Rice and coconut
A leaf in the pot with jasmine rice or coconut milk.
Dressings and dips
A pinch of peel in lime-and-chilli dressings and dips.
Recipes
Two Thai classics
A soup scented with the leaves and a curry paste built on the peel.
Tom yum goong
Hot and sour prawn soup · serves 4
1 litre prawn or chicken stock
6 makrut lime leaves
2 stalks lemongrass, 8 slices galangal
2–5 Thai chillies, 200 g oyster mushrooms
3–4 tbsp Thai chilli paste (nam phrik phao)
3 tbsp fish sauce, 120 ml lime juice, 1 tsp sugar
12–15 large prawns, coriander leaves
Bruise the lemongrass and cut it into short pieces. Twist the lime leaves, tear them and pull out the ribs. Simmer the stock with the lemongrass, galangal, chillies, mushrooms and leaves for 5 minutes. Stir in the chilli paste and fish sauce, bring to the boil, add the prawns and turn off the heat as they turn pink. Add the lime juice, taste for sour, salty and sweet, and finish with coriander.
Grind the dry spices to a powder. Pound or blend in the chillies, then the lemongrass, galangal, makrut peel and coriander roots, then the garlic and shallots, and finally the shrimp paste, until smooth. For a curry for four, fry half the paste in thick coconut cream until fragrant, then add meat or vegetables and the rest of the coconut milk.
Ground makrut peel with whole and halved fruits
Beyond the classics
Makrut’s sharp citrus in new pairings — not Thai tradition:
Makrut salt: ground peel with flaky sea salt for grilled fish, prawns or avocado
Fragrant rice: jasmine rice cooked with one or two dried leaves
Citrus shortbread: a pinch of ground peel in shortbread or a coconut cake
Coconut cream: coconut milk warmed with a torn leaf for panna cotta or ice cream
Beyond flavour
Tradition and research
Makrut lime is first of all a kitchen plant. In Thai homes it has also long been used for hair, cleaning and ritual, and its oils interest researchers today.
What researchers are exploring now
Two studies on the questions that matter most in the kitchen — how cooking and drying change the leaf:
Researchers in Thailand cooked makrut leaves six ways — blanching, boiling, steaming, frying, roasting and hot-air drying. Citronellal, 56 % of the scent compounds in fresh leaves, rose in dry heat and fell in water, while citronellol rose in blanching and boiling. Steamed leaves kept the most phenolic compounds.
An Indonesian team compared fresh green leaves with milled, dried, and dried-and-milled leaves. Every treatment lowered the oil yield and the share of citronellal, and darkened the oil. Their advice to oil makers who want the most citronellal: fresh green leaves, without drying or powdering.
Educational product information. Not medical advice. If you are pregnant, breastfeeding or taking medication, consult your doctor before using a new botanical product.
