Of all the useful native Australian plants, the magnificent rainforest lemon myrtle tree is my culinary favorite. These attractive trees grow to around 26 feet (8 m) tall and may even reach 60 feet (20 m) in tropical conditions. The growth is bushy with low branches covered in dark green, oval, tapering leaves that look like bay leaves. In autumn, small white flowers bloom in thick, soft clusters making this an excellent tree to grow for its appearance as well as its usefulness. Both the flowers and fruits may be eaten, as well as the leaves.
The aroma of lemon myrtle is similar to a blend of lemon verbena, lemongrass and kaffir lime with a haunting eucalyptus background, something that is particularly noticeable after rain. The flavor is distinctly lemony and tangy, with distinct lime zest notes and a pleasantly lingering, slightly numbing camphor aftertaste. Lemon myrtle's citral content (the component that gives it a lemon flavor) is around 90 percent, compared with around 80 percent in lemongrass and only 6 percent in lemons. Powdered lemon myrtle leaf is coarse, pale green and when fresh releases all of these aroma and taste attributes.
Origin and History:
Although there are no records to establish the exact antiquity of native Australian herbs and spices, these hardy yet frost-sensitive trees have been growing wild in the coastal areas of New South Wales, Victoria and South Australia for many thousands of years. When these were identified and classified, the botanical name Backhousia was given to this species after a Yorkshire nurseryman, James Backhouse. Lemon myrtle trees are now grown in South Africa, the southern United States and southern Europe, and in more recent times, propagation with a view to extracting the essential oil has taken place in China, Indonesia and Thailand. The most active undertakings in the 20th century, dedicated to the development of a culinary and essential oil industry revolving around lemon myrtle, were thankfully in this plant's native Australia.
Weight per teaspoon (5 ml):
whole dried leaf: 0.5 g ground: 2.2 g
Asian dishes when added in small amounts grilled chicken, pork and fish shortbread cakes and muffins
blends containing native Australian herbs and spices stir-fry seasonings laksa spice blends green curry mixes
Suggested Quantity per Pound (500 g):
red meats: 1/4 to 1/2 teaspoon (1 to 2 mL) ground dried leaf white meats: 1/4 to 1/2 teaspoon (1 to 2 mL) ground dried leaf vegetables: 1/2 teaspoon (2 mL) ground dried leaf carbohydrates: 1/2 teaspoon (2 mL) ground dried leaf
allspice cardamom chili cinnamon cloves coriander leaves and seeds cumin seed fennel seed fenugreek seed galangal ginger mustard nigella paprika tamarind turmeric Vietnamese mint
Buying and Storage:
Fresh lemon myrtle leaves can sometimes be bought from specialty native Australian foods suppliers; however, the more convenient whole or powdered lemon myrtle leaf is readily available from herb and spice shops and many gourmet food retailers. Because of the volatility of the essential oil, it is important to purchase only small quantities (say less than 1 2/3 ounces/50 g for normal household requirements) of freshly produced lemon myrtle powder in airtight packaging. Store in the same way as other delicate green herbs, in a well-sealed container in a cool, dark place.
Lemon myrtle has an incredibly varied number of uses, as its aromatic lemonyness goes with almost any food. There are, however, two basic guidelines worth remembering to achieve the best results. One is to add only a small amount, say 1/4 to 1/2 teaspoon (1 to 2 mL), or 1 to 2 leaves, to 1 pound (500 g) of meat or vegetables, then taste before adding more. The other is to put lemon myrtle only in recipes that cook for a short time, never subjecting it to extreme temperatures for more than 10 to 15 minutes. The reason for this caution is that when too much lemon myrtle is used, or when it is cooked for too long, the flavor-giving volatile oils will be destroyed and a sharp, possibly unpleasant eucalyptus flavor will dominate.
Lemon myrtle is an excellent substitute for lemongrass and complements Asian stir-fry dishes, especially those with chicken, seafood and vegetables. Broiled chicken, pork and fish are given a lift when a little lemon myrtle is sprinkled on before cooking, as is smoked salmon served cold. While some cooks like to put lemon myrtle in cakes and muffins, I generally prefer it in sweet things that are cooked more quickly at a lower heat, such as blinis and pancakes. In these quick-cooking applications, infuse lemon myrtle in a little hot water to bring out the flavor first. Shortbread cookies are particularly delicious when flavored with ground lemon myrtle. However, they are best consumed within a few days of baking, as the fresh lemon notes deteriorate quite quickly.