Lemon Myrtle: Australia’s Citral-Rich Lemon Herb, Its Flavor and Uses

Lemon myrtle is about as lemony as a leaf gets. Katzer’s Spice Pages passes along a description of its scent as “more lemon than lemon,”¹ and its oil is almost all citral, the compound most responsible for a lemon note.² It’s the leaf of Backhousia citriodora, a shrub or small tree native to Queensland, Australia. Cooks use the dried, ground leaf much like lemongrass or kaffir lime leaf, and in tea.

At a glance

Flavor and aroma

Lemon myrtle tastes intensely of lemon peel and lemongrass, with a faint eucalyptus-like, herbal edge and none of a lemon’s sourness. Katzer describes the aroma as “intensive, refreshing and very, very lemon-like,” and the taste as very intense, pleasant and warm. He puts it with lemon verbena, lemon balm and lemongrass as having the purest lemon scent of all the lemon-scented herbs.¹

The compounds

Citral comes as two isomers, neral and geranial, and it dominates lemon myrtle oil:³

The review notes that both citronellal and citral can give a lemon note, and citral is the preferred one. Of the many sources of citral, it rates B. citriodora as the best.² For other lemon-scented herbs, see lemongrass and lemon verbena vs. lemongrass.

Origin and history

The name. The genus is named after the English botanist James Backhouse, and the botanist Ferdinand von Mueller named the species. Citriodora means “lemon-scented.”¹

Where it grows. Queensland is its only native area. Katzer describes it as rare in the wild, limited to Queensland and considered endangered.¹

Aboriginal use. A lemon myrtle grower quoted by FoodNavigator in 2015 said Aboriginal Australians have used it as a flavoring and medicine “for 40,000 years.”⁴ That’s a grower talking, not an ethnobotanical record. Specific traditional uses that often get described, like inhaling vapors from heated leaves for colds, couldn’t be traced to a documented source.

Commercial history. Katzer says the plant has been cultivated since the early 1990s.¹ FoodNavigator reports that interest in Australian native foods around the Sydney 2000 Olympics helped revive it, and that Qantas later used it as a lemon flavoring on its premium menus.⁴ A few other details float around: citral’s identification in lemon myrtle by the German firm Schimmel & Co. in the late 1880s, commercial distillation at Eumundi in the early 20th century, and use in soft drinks during World War II. We couldn’t confirm any of them in the sources we checked, so they’re left out.

How it is used

• Poultry and seafood. Katzer says lemon myrtle leaves often flavor poultry or seafood, and one or two leaves give roast chicken a special touch.¹
• In place of lime leaf. Australian cooks tend to use lemon myrtle instead of kaffir lime leaves in Southeast Asian recipes, though Katzer finds its very pure scent doesn’t go so well with pungent fish pastes.¹ See kaffir lime leaves.
• Dressings and condiments. It’s popular in herbed vinegar, mayonnaise and vinaigrettes.
• Tea and baking. It’s popular as a lemon herbal tea, and it shows up in teas, breads, biscuits, cakes, cheeses and chutneys.

Ground leaf is strong. Start with a small pinch, taste before adding more, and add it late to sauces. It’s also a handy way to get lemon flavor into cream or custard without adding acid.

For other Australian native flavorings, see Australian spices. For other lemon herbs, see lemon verbena, lemon balm, lemon thyme and lemon basil.

Buying and quality

Dried lemon myrtle should be green, not brown, and smell strongly of lemon when crushed. FoodNavigator reported in 2015 that farmgate prices for leaves reached up to US$25 per kilo, and that one producer had moved production to Malaysia.⁴

Storage

Keep dried or ground leaf airtight and away from light and heat. We couldn’t find a shelf-life figure from a regulator or standards body. If it barely smells of lemon when you crush it, it’s gone stale.

Health claims and safety

What the research covers. In lab tests summarized in the 2021 review, lemon myrtle oil showed significant antimicrobial activity against Staphylococcus aureus, including methicillin-resistant strains (MRSA).² A 2022 study measured the oil’s activity against clinical S. aureus strains in the lab, and cites another study where it produced a large inhibition zone against MRSA.³ These are test-tube results on the concentrated oil. They don’t show that eating lemon myrtle prevents or treats infections.

The review also says lemon myrtle extract is a source of lutein and other antioxidants, along with folate and the trace minerals magnesium and calcium.² We couldn’t find measured amounts per serving, so claims that it protects eyesight or supplies meaningful calcium can’t be backed up. Claims that it fights cancer couldn’t be traced to any review or regulator, and we don’t make them.

Safety of the oil. The review reports that in lab tests, both lemon myrtle oil and pure citral were highly toxic to human cell lines, and that citral was absorbed into skin. Citral irritates and sensitizes skin at high concentrations, and the review cites a recommendation to keep the oil below 1% in topical products. Australia’s Therapeutic Goods Administration had approved three lemon myrtle essential oil medicines by 2006.²

All of that is about the concentrated oil and pure citral, not the small amounts of dried leaf you’d cook with. We couldn’t find a regulator assessment of the culinary leaf.

Substitutes and comparisons

• Lemongrass and lemongrass substitutes
• Lemon verbena and lemon verbena substitutes
• Lemon balm vs. lemon verbena
• Kaffir lime leaf substitutes
• Lemon pepper