Lemon myrtle vs Lemongrass
The short answer
Both taste of lemon for the same molecule — citral — and lemon myrtle has more of it than almost any plant, about nine-tenths of its leaf oil. Lemongrass is a grass stalk, bruised and simmered in Southeast Asian curries and broths, with a softer, grassier lemon. Lemon myrtle is an Australian rainforest leaf, dried and ground, far more intense, and used by the pinch in baking, tea and on fish. As a substitute for lemongrass it needs a fraction of the quantity and brings a sharper, more candied lemon.
Side by side
| Lemon myrtle | Lemongrass | |
|---|---|---|
| Botanical identity | Backhousia citriodora F.Muell. | Cymbopogon citratus (DC.) Stapf |
| Part used | leaf | leaf |
| Origin | The subtropical rainforests of central and south-eastern Queensland. | Maritime Southeast Asia and southern India, where Cymbopogon citratus has been grown so long that it is not known in a genuinely wild state — it rarely flowers in cultivation and is propagated entirely vegetatively. |
| Flavour notes | lemon, zesty, herbal, sherbet, faintly bitter | citrus, grassy, floral, clean |
| Heat | Scoville does not apply | Not established |
| Flavour | Strong lemon with a slight bitterness and a green, herbal finish. Used in small amounts. | Mildly citric and slightly bitter, mostly delivered as aroma rather than taste. Fresh stalks are noticeably more fragrant than dried, which loses much of the top note. |
| Aroma | Intense, clean lemon — sherbet and zest — with a faintly eucalyptus or herbal edge. The leaf oil is typically ninety per cent or more citral, which is why it smells so purely of lemon. | Clean, bright and lemon-like, with a grassy green edge and a faint soapy or floral note. It carries the citrus aroma without any of the sourness, which is the reason it is not interchangeable with lemon. |
Can you swap them?
Substitution is directional: the answer is often different in each direction, and both are recorded.
Lemongrass
AcceptableUse: 3–4× by volume — Three to four times as much lemongrass, because lemon myrtle carries more citral.
Both taste of lemon because of citral. Lemongrass adds a grassy base and is fibrous, so it is infused and removed rather than stirred in; the lemon is softer.
| Flavour | Aroma | Colour | Heat |
|---|---|---|---|
| close | close | different | n/a |
Works for
- Infusions, syrups and custards
- Marinades for fish and chicken
Does not work for
- Shortbread and baking where the ground leaf is mixed into the dough
- Dry rubs and crusts
Which should you buy?
Lemon myrtle
Buy small quantities of ground leaf for baking and cooking, and whole leaf for tea. Neither keeps its lemon for long once opened.
Lemongrass
Buy fresh and freeze what you will not use within a fortnight. This is the rare aromatic where freezing is genuinely close to the fresh article, and it makes the dried form hard to recommend for anything but tea.
Full detail on lemon myrtle and lemongrass, including evidence grades and sources for every claim above.