Pan-Thai — cultivated throughout the country; used across all regional cuisines in different proportions
Lemongrass (Cymbopogon citratus, takhrai) is both an aromatic compound and a textural element in Thai cooking, and the processing technique determines which role it plays. The outer two or three layers of the stalk are fibrous and tough — they are removed before any application. The inner, pale yellow-green core is tender and carries the highest concentration of citral (the compound responsible for the lemon-citrus scent). For pastes, the tender inner section is sliced into thin rings, then pounded into fine paste — coarser grinding leaves fibrous strands that catch between teeth. For soups and infusions, the whole stalk is bruised with the flat of a knife to rupture cell walls and release essential oils before adding to the liquid.
Lemongrass provides the citrus-floral high register of Thai curry pastes — working in tandem with kaffir lime leaf, it creates the characteristic bright top note that lifts heavy coconut-based curries.
{"Peel minimum 2–3 outer layers before any application — these are woody and unpalatably fibrous","For pastes: use only the bottom 10–12cm (tender core); slice thinly before adding to mortar","For soup/infusion: cut into 8cm sections and bruise firmly with knife flat or mallet — do not cut","Fresh lemongrass is significantly superior to dried for paste work; frozen acceptable","The root end (white, fibrous bulb) is discarded; the base of the tender stalk is the most aromatic section"}
When buying fresh lemongrass, the bottom should be firm, pale, and slightly moist — soft, brown, or dry stalks have lost most of their essential oils. For paste preparation, a microplane grater or food processor blade can substitute for the mortar, but only if the outer layers are very thoroughly removed — even small fibrous strands become evident in the finished paste.
{"Using the entire stalk in pastes without removing fibrous outer layers — results in stringy, under-blended paste","Using lemongrass powder in paste — it has essentially no volatile oil content remaining","Adding bruised lemongrass pieces to a dish and forgetting to remove them before service","Cutting rather than bruising lemongrass for soups — cutting releases bitterness; bruising releases aromatics"}