Lemongrass: Citral, Origins, and How Cooks Use the Stalk

Lemongrass tastes of lemon without the sourness, and in a dish it brings brightness and perfume that work alongside lime instead of replacing it. It’s Cymbopogon citratus, a tall, tufted perennial grass grown across the tropics, and its scent comes from an essential oil whose main constituent is citral.¹ Where it first grew is a genuinely open question: it’s known only from cultivation, and even Kew’s own pages give different native ranges. Below: the chemistry and how much it varies, how to cook with it, and what the health evidence shows.

At a glance

What lemongrass is

PROSEA describes lemongrass as a perennial, tufted, aromatic grass with lots of upright stems up to 2 m tall (occasionally 3 m) and linear leaf blades 50–100 cm long.¹ Most of the flavor is in the fibrous stalks and the slight bulb at the base.

Lemongrass and citronella

Lemongrass belongs to the genus Cymbopogon, and related species in the same genus yield citronella oil, the familiar mosquito repellent. FDA’s list of essential oils generally recognized as safe names two species under lemongrass, C. citratus and Cymbopogon flexuosus.⁴ PROSEA’s entry on C. citratus separates its oil from “East Indian” lemongrass oil, which has little or no myrcene.¹

Flavor and aroma

The flavor is rich lemon without the acidity. The oil smells very strong, fresh-grassy, lemon-like and herbaceous or tea-like. In a dish it brings brightness and perfume, not sourness, so it works alongside lime and other acids instead of replacing them.

Citral, and how much it varies

PROSEA names citral as the main chemical constituent of lemongrass oil. Citral is a mix of two stereoisomers, geranial and neral, and myrcene, limonene and geraniol are among the other components.¹ The proportions aren’t fixed. Here are the figures PROSEA reports, each with its own scope:

These are oils distilled from the plant, not measurements of a fresh stalk, so don’t add the ranges together into a single “citral percentage”. PROSEA gives no total citral figure for typical oil. The Ethiopian result shows that some lemongrass oils are low in citral altogether. In the oil trade, citral content is the quality measure that matters most.¹

Origin and history

Nobody’s sure where lemongrass comes from, and the sources disagree:

Kew’s Flora of Somalia entry also describes it as known only as a cultivated plant. Kew lists it as introduced across tropical Africa, Asia, the Americas (including Florida) and the Pacific islands, including Hawaii.² The common claim that lemongrass is native to Thailand, India, Sri Lanka and Burma doesn’t match any single source, and nothing supports the idea that it’s an “island plant”.

How lemongrass is used

PROSEA suggests the leaves were probably first used to flavor food and drinks, and notes that it’s grown as a condiment in home gardens throughout Southeast Asia.¹

• Mainland Southeast Asia. In Thailand, Laos and Vietnam, cooks pound lemongrass with garlic, makrut lime leaf and other herbs into thick curry pastes. See Thai spices and kaffir lime leaves.
• Indonesia. In Java, lemongrass goes into a popular sherbet, its leaf sheaths go into spicy sauces and fish dishes, and the heart of young shoots is eaten with rice.¹
• Tea. The stems are widely used in teas and other drinks.

Technique

The stalks are fibrous, so they usually get steeped in oil or stock and pulled out before serving, while the tender shoots at the center can be chopped finely and eaten. Outside Southeast Asia, lots of cooks rely on lemongrass powder and dried stalks.³ So the claim that lemongrass is mostly used dried and powdered is true only of that outside market, by Britannica’s account. For more, see cooking with lemongrass and lemongrass uses.

Buying, quality and trade

For the essential oil, PROSEA says citral content is the overriding quality measure, and that synthetic citral is too expensive to be worth using to cut it.¹ For fresh lemongrass, look for firm, heavy stalks with a pale, tight base and a strong lemon smell when cut.

The trade figures are old. PROSEA estimated world lemongrass oil production in 1986 at 650 tonnes, worth about US$4.3 million, mostly from Central and South America (Argentina, Brazil, Guatemala, Honduras), and puts average US imports in 1992–1994 at 80 tonnes a year.¹ We couldn’t find a current statistical source.

Storage

We couldn’t find published guidance on storing fresh lemongrass stalks from a regulator or extension service, or a shelf-life figure for dried lemongrass. PROSEA notes that freshly distilled oil quickly gets less soluble in storage because its myrcene polymerizes, which matters for the oil, not for the stalks in your kitchen.¹

Health and safety

Memorial Sloan Kettering’s herb database says lemongrass is used in traditional medicine and aromatherapy but that human studies are limited. Most claims about sleep, anxiety and digestion rest on lab or animal work, and in clinical studies lemongrass tea didn’t reduce anxiety or have a calming effect. It lists possible side effects of taking it by mouth, including dizziness, drowsiness, dry mouth and more frequent urination, and skin rashes from use on the skin.⁵ Kew notes that lemongrass oil can cause contact dermatitis.²

FDA lists lemongrass oil among essential oils generally recognized as safe for their intended use in food.⁴ We don’t claim lemongrass treats or prevents anything. Claims that it lowers cholesterol, treats diabetes or cancer, or cures infections weren’t supported by the human evidence we found. According to Kew, lemongrass oil has also been used as an insect repellent and to perfume beauty products.²

Substitutes and comparisons

Lemon zest with a little ginger gets you part of the way. See lemongrass substitutes for the full list.

• Lemon balm vs. lemongrass
• Lemon verbena vs. lemongrass
• Galangal, ginger, lemon verbena, lemon balm