A tree in its fifth year will bear approximately 1 kg of nuts-in-shell (NIS) and after twelve years the yield is about 15 kg. Once established, a well managed, healthy orchard could have an infinite lifespan.

Processing

After the mature nuts are harvested, macadamia nuts then go through a stringent process in order to utilise the nut, ensure quality and prepare them for the trade or consumers.

1. Dehusking - The fibrous outer husk of the Macadamia is normally removed within 24 hours of harvest to reduce heat respiration and facilitate drying.

2. Drying – At harvest the nuts have a moisture content of up to 30%. Drying can take up to three weeks, during which time the kernel shrinks away from the inside of the shell, allowing the shells to be cracked without damaging the kernel. Before shelling the nut’s moisture content can be no more than 3%.

3. Cracking – 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. Machinery has either a fixed blade and cutting blade, or a combination of rollers and a base plate to compress and crack the shell.

4. Sorting – This removes any pieces of shell and bad nuts. The nuts are separated by weight and size.

5. Further drying – Kernel moisture is reduced to a maximum 1.5% - this is essential to maximize shelf life and quality of the end product.

6. Packing – The kernels are packed into laminate bags, flushed with an inert gas (either nitrogen or carbon dioxide) and partially vacuumised to prevent the kernels rubbing in transit and ensure good shelf life.