Lemongrass

A tall tropical grass whose fibrous stalks carry the scent of lemon without any of its sourness — the perfume of Thai soups and curry pastes, Vietnamese grills and Indonesian braises.

Where it comes from

Lemongrass is native to the Indian subcontinent and Southeast Asia and has been grown there for cooking, medicine and perfume for millennia; its oil, citral, is the same compound that scents lemon peel. In the kitchen it is a Southeast Asian ingredient above all — tom yum, tom kha, green curry, Vietnamese lemongrass chicken and the Indonesian spice pastes called bumbu all depend on it — and it came late to Europe and the Americas, where it is now grown commercially in warm climates.

Only the lower stalk is used. The outer leaves are papery and tough; the tender pale core, about the bottom ten centimetres, holds the flavour. Bruised or crushed, it releases its aroma into a liquid and is then removed; sliced hair-thin or pounded to a paste, it is eaten.

Varieties

• West Indian lemongrass (Cymbopogon citratus) — The kitchen species: thick stalks, bulbous base, strong lemon scent. What is sold fresh in Asian shops.
• East Indian lemongrass (C. flexuosus) — Grown more for oil than cooking; thinner, slightly harsher.
• Dried and powdered lemongrass (sereh powder) — Convenient but flat; used in Indonesian spice mixes.

In the kitchen

Trim the root end and the grassy tops, peel off the dry outer layer, then either bruise the stalk with the back of a knife and drop it in whole — for soups, broths and braises, removed before serving — or slice the tender core very finely across the grain for pastes and stir-fries, where the fibres will not soften.

Pounded in a mortar with galangal, garlic, chilli and shrimp paste it becomes the base of a Thai curry paste. It pairs with coconut, lime, ginger and chilli and stands up to long cooking without losing its scent.

Choosing and keeping

Stalks should be firm, pale green to cream at the base and fragrant when scratched. They keep two or three weeks in the fridge wrapped, and freeze perfectly — freeze them whole and slice or bruise from frozen.

Dried lemongrass and the powder have little of the fresh scent and are a poor substitute. Lemongrass paste in jars is acceptable for a soup base.

Lemongrass is tagged on 83 dishes from 19 countries in the atlas. These notes are written from general knowledge and carry no per-fact citation — see About.