Macadamia is a genus of eight species of flowering plants in the family Proteaceae. Only two of the eight species, Macadamia integrifolia and Macadamia tetraphylla, produce edible nuts. Nuts from the other six species are poisonous and/or inedible - the toxicity is due to the presence of cyanogenic glycosides.
History of the macadamia
Although known to Australia’s indigenous people as the “Kindal Kindal”, it wasn’t until 1853, that two European botanists discovered the macadamia nut growing in the rainforests of Eastern Australia. They named the tree after Dr John Macadam, a friend and noted philosopher, chemist, medical teacher and politician.
For a while the macadamia tree was grown only for ornamental purposes but in the 1890s the macadamia journeyed from Tasmania to be cultivated in Hawaii, the first time macadamias were grown commercially. Macadamias are the only Australian native plant to be developed as a commercial food crop.
How do macadamia nuts taste?
With an irresistible soft crunch, they offer a smooth, buttery-rich, yet delicate, slightly sweet taste.
Where do they grow?
Macadamia trees will only grow in tropical climates. Australia is the world’s largest supplier producing nearly half of the world’s macadamia nuts. It boasts over 800 plantations with more than 4 million trees, most of which are on its subtropical east coast.
Currently the second biggest producer in the market, South Africa is on course to increase its output dramatically in the next few years. Other key producers include the USA (Hawaii, California and Florida), Brazil, Guatemala, Costa Rica, Malawi, Zimbabwe and Kenya.
How do they grow?
There are two types of nut: tree nuts and ground nuts (legume) which grow underground like peanuts - macadamias are a tree nut. Macadamia trees need a warm climate, plentiful rainfall and deep, rich soil to produce the perfect nut. The tree is evergreen and takes 10 years of cultivation before it bears a crop (although macadamia trees will produce nuts for up to 100 years).
The trees grow to a height of 12-15 metres with dark shiny leaves and branches that bear sweet smelling creamy white flowers called racemes. The flowers produce “nutlets” which ripen into nuts. A mature tree can yield around 15kg of nuts per year. By early autumn large clusters of plump green nuts are visible and harvesting commences in late autumn and through the winter months. Unlike other tree nuts, macadamias fall naturally to the ground when they are ready and are collected by mechanical harvesters with spoked wheels.
After the mature nuts are harvested the outer husks are removed, revealing a hard shell. The nut is then dried to ensure its moisture content is no more than 3% when they are shelled. Precision technology is needed to crack the tough shell (it requires about 300 pounds per square inch of pressure to crack!) without damaging the delicate, marble sized, light golden kernel. The kernels are then inspected, graded and packed, ready for distribution.
Where are they available in the UK?
Macadamia nuts, and products containing the nuts, such as oil, cereal bars and desserts, are available in most UK supermarkets and specialist health stores. Sales of Macadamia nuts in the UK currently exceed 500 tonnes. The whole nuts category is growing in popularity as consumers choose more health-conscious snacks. According to Euromonitor, UK nut sales grew 65 per cent between 2001 and 2006 - from £169.6 million to £280.46 million. Tastes within the nut market itself are changing as consumers head for the premium end of the market, choosing luxury nuts with established health benefits. Sales of premium nuts grew by 99% from 2001-2006.
Tips for eating macadamias
Macadamias are widely used by chefs and food lovers in a variety of sweet and savory dishes and have many uses including:
- Keep as a healthy snack
- Add a handful to breakfast cereal or make a macadamia muesli by mixing rolled oats, bran, seeds, dried fruit and macadamias
- Add to salads or toss through vegetables or fried rice
- Use chopped macadamias in stir fries or Asian style cuisine
- Use crushed macadamias in crumbles and toppings or add to yoghurt with chopped fruit
- Add to baked goods like muffins, cakes, pastries, bread or fruit loaf
- Add to savoury dishes such as pasta, risotto, curries or casseroles
Recipes
For plenty of recipe suggestions for snacks, starters, mains or desserts, please click on the links below:
Macadamias and animals
Macadamia nuts form the staple diet of the Hyacinth Macaw in captivity. Native to South America, these large parrots are one of the few animals, humans aside, which are capable of cracking and shelling the nut.
Macadamia nuts are toxic to dogs, causing weakness and an inability to stand within 12 hours of eating. The exact cause of the why this happens is not known, but recovery is usually within 48 hours of ingestion.
