Fresh from the tree, a stalk of unhusked nuts

What to do with your Macadamia nuts

TLC

So you have a macadamia tree growing in your back yard. It may need a bit of help to produce a crop of nuts. We are fortunate in New Zealand to have very few pests. Green vegetable bug is the macadamia nut growers' nemesis but appears to be less of problem for the home gardener. Nevertheless, keeping the ground tidy under the tree will reduce insect pest problems and enable you to find the nuts more readily. Rats love nuts too and may have to be culled by trapping or poisoning to cut down on the competition. Removing old birds' nests, which provide homes and feeding platforms for rodents, is helpful. Possums can be destructive and may need attending to; they chew on the husks and may knock many nuts off the tree.

When to harvest

Some varieties of macadamia drop nuts when ripe; others have to be picked. Typically, nuts begin dropping in late autumn but the timing depends on the variety. Once they start to drop they shouldn't be allowed to lie on wet ground For nuts that have to be picked, check for ripeness by removing the husk and looking at its inner surface. If the colour is a rich and dense brown the nuts are ready to harvest.
The green husks must come off within 2-3 days or the nuts will spoil. Then the nuts need to be dried in an airy place out of the direct sun and away from rats and mice. Freshly picked nuts contain 28% moisture and store better after air-drying. Before cracking it is best to dry the nut to less than 3% moisture for a crisp textured kernel. A dehydrator or cool oven will do this. After using the oven, turn elements off and put in the nuts (spread out on a baking tray) and leave overnight. When the weight stops dropping or the nut rattles inside the shell, you will know they are dry.

Cracking

The macadamia nut is notoriously hard to crack and humans have come up with ingenious ways to get the kernel out. A hammer or vice will do the job, but refinements on these techniques are advisable. Australian aborigines used a rock with a nut-sized cavity and a hard base. For hammerers, a rubberised doormat with holes the right size to steady the nut, improves efficacy and speed. The safest home crackers use the same principle as a vice, for example the TJ's model from Queensland. We provide a drying and cracking service for small growers in our vicinity if it is needed.

Processing

Raw kernels should be crisp and fragrant. To keep them this way store in good airtight containers such as screwtop jars or ziplock bags. Otherwise they will absorb moisture and gases from the air. Cooks recommend that macadamias be roasted slowly, say 100 to 110 C for 20 minutes. They will brown quickly at higher temperatures

Cooking

From curry pastes and pesto, dukkah and crumb coatings, a substitute for flour, a base for sauces, sweet dishes or snacks the macadamia is a truly versatile comestible. You can make a delicious and useful milk from macadamias as well. See our recipe section for ideas.