Lemon Myrtle (Backhousia citriodora) a native of Queensland's tropical rainforests has found a new niche on the Mid North Coast of New South Wales. Oil extraction from the leaves of the Lemon Myrtle by steam releases the volatile citral oils and gives a beautiful lemon essential oil full of fragrance and flavour. Some what like a cross between Lemon oil and Lemongrass oil with a hint of Kaffir Lime. Foods can be flavored with the leaves and the oil. Both impart a strong lemon scent to the dish. The pure extracted essential oil is extremely strong, as a result it can cause irritation and even burns in some sensitive individuals if applied directly to the skin in its undiluted state. The oil produced is very intense. You will not require much to produce a massage oil, I would recommend about 5 drops to 100ml of carrier oil. The oil can be used with great success in cooking. When combined into a soap it presents no negative effects and produces a fine fragrance.
On the North Coast of NSW
Inland from Port Macquarie there is a small island between the meandering forks of the Hasting River. Here grows a bountiful crop of Lemon Myrtle trees, purposely planted to reap the benefits of this high quality essential oil. These plants have been derived from the seeds of top quality natural stands of Backhousia citriodora growing in the tropical coastal rainforests of north eastern Queensland. This variety is well suited to the Northern Rivers area of NSW. Although the seeds have a very low germination rate of 3-4% they still provide a reasonable crop of viable seedlings with which to experiment if they are set up in a greenhouse on mass. The young plants were cultivated in nurseries and evaluated for their growth rate and oil quality. Then after some considerable expense the most viable trees where chosen for vegetative propagation. Once hardened off the young trees are planted out in rows and nurtured to maturity with irrigation and organic soil nutrients (cow manure).
Author standing with a loaded basket
In Australia the financial success of any commercial venture must be well researched and highly productive in order to counter the effects of high wages and also if the business is involved in international trade the low value of the dollar against international currencies will demand efficiency or the production will not survive.
Lemon Myrtle harvest and loading “the basket”
The Commercial Harvest
The trees respond well to pruning and as you can see from the photos, the harvest can look quite severe. This is not a problem however due to their low branching nature, they recover very well for the following years harvest. This is usually done in April.
Loading a basket of Lemon Myrtle into the still
It takes several years for a Lemon Myrtle tree to mature and produce a root system capable of supporting regrowth before a commercial harvest can be cut from the foliage. Leaves are steam distilled directly after harvest for the best quality oil.
Sealing the still
The Distillation Equipment
The still is built into a trailer, making it portable. The trailer holds about 150 centimeters of water and a propane gas setup heats the water to boiling point. The extraction process takes about 30 minutes per batch. The steam generated in the trailer rises through the lemon myrtle in the basket. The air gap at the top leads to the condenser. Water from a garden hose running slowly through the condenser provides the necessary cooling. The lemon myrtle oil and hydrosol fill the collector, this separates naturally because the oil is lighter than the water. The hydrosol is drained off from the bottom after the oil floats to top. The last photo shows the pure lemon myrtle essential oil being tapped into a glass jug.
Pouring the Lemon Myrtle oil from the collector
Notes on Cultivation
The big issue for this tree when growing in temperate zones is frost. If you have an interest to grow this tree as an ornamental and for the culinary use of a few leaves I can offer the following useful information. These tree grows up to 10 m in a domestic garden. They respond well to pruning. Lemon Myrtle will grown in containers with great success. Provide plants with a sunny position and sheltered them from frost and wind, especially when young. I have read that mature trees in a sheltered position have survived frost to –8° C. Frankly I think that is really too much for the plant to bear. If the frost went down that low I would be lighting a few fires at the ends of the rows. The plant thrives in acid to neutral rich moist organic soils, however it will tolerate sandy or heavier textured soils.
Used in products like Lemon Myrtle Soap it will produce one of the best lemon fragrances available for this purpose. Melt and pour enthusiasts can extract oil on the kitchen stove. Also add the crushed leaves to the soap as a scrubber. Another use popular with home garden specimens is to dry and crush the leaves into a powder for a spice with a better than lemon zest effect.