Dry Your Own Macs!

   Macadamia Flowers
The following was culled from an exchange of email messages through one of the fruit groups I thought it might be good to write up advice for those with macadamia nuts to store.

Young trees are very ornamental and add to the general beauty of the landscape. They can also be precocious, producing some fruit from a young age. A good macadamia tree can yield up to 200 pounds of nuts in a year, a bit too many to eat all at once you may want to prepare some for storing, sale and or giving to friends. If you are determined not to use them to feed the squirrels you may want follow Hawaiian grower Aaron Bandy's advice on drying.

Aaron: "I ship to Hawaiian Host but I have sent the unshelled nuts to parrot breeders, especially Hyacinth Macaw breeders. They can crack the nuts easily. The nuts need to be hulled and dried even before I ship them the Hawaiian Host. They take moisture content readings to determine the payment. The less moisture the more valuable, but the less moisture the less weight so there is a happy in-between. The first year I moved here permanently and took over the operation I purchased a dehumidifier and brought the moisture content down to 7%; it is generally around 15%. At the end of the year I compared the increased value with the increased electric costs and found no benefit so I have not run the dehumidifier since."

Rather than a dehumidifier a backyarder might use an inexpensive food dryer. Spread the nuts out in a single layer for each level and keep the heat very low (or off) so as not to alter the flavour, remember that excessive heat can affect the oil. Aiming for a low end moisture content will assist in storage.
Mac Flower close-up
Aaron: "Mac nuts are mature when they fall from the tree. We pick them up then and I hull them. You might place them in welded wire bins placed on a 2x4 stand so that the air can circulate around the nuts. The shells will crack if you place them in the sun. I have my setup on a covered lanai what has wire on 3 sides. The hulls will shrived and has a crack that runs vertically. I would wait for the hulls to shrink and then they should be easy to remove. I would then leave the hulled nuts in the basket and see their color lighten up due to moisture loss. I determine if they are ready to send to the  processors by shaking a few and feeling the kernels move inside them. When the water content is high they will cling to the inside of the shells, as someone pointed out. After shelling you can place them in freezer bags and put them in the freezer. Some people put the shelled nuts in jars but you have to watch for rancidity that is avoided by freezing. Mac Nuts have been found to be nutritious and not the health hazard originally thought. We have mac nut oil here that is used over salads."

For a home owner using an inexpensive dryer may be easier than wire bins in the shade. The wire bins, if enclosed,  would offer some squirrel protection. Aaron mentioned cracking if dried in the sun, this would allow for the introduction of insect and or disease organisms into the nut. For the person with one or two trees a dryer would allow them to bring the moisture content down which increases storage success. Freezing, of course aids greatly in preventing spoilage and preserving flavour.

A note on shelling and hulling. Macadamia nuts grow much like the pecan and several other nuts, they start out with a protective hull that splits away and is usually removed before sale. Their shell, on the other hand, is what gives them their reputation for hardness. It takes some practice but you can crack macs at home and, there are several crackers offered in catalogues. So called 'thin shell' nuts have a defect in the shell which makes them easier to open. Some growers report that this defect also allows for the introduction of fungus that can spoil the nuts.

However you dry your crop, check for dryness as Aaron suggests by shaking to see if the nut is free in the shell. To get a lower moisture content let them dry a couple of days past the loose in the shell stage. (You can also weigh a pound of nuts at the start and re-weigh to see what percent of weight loss has occurred.

Remember, if you opt for drying on a lanai or porch you may need to protect them from squirrels and other pests. There is also some mention in veterinary literature as to some dogs being sensitive to the Macadamia - if you are not sure about your pet don't feed them macs. In my experience I have met only a single person who had an allergic reaction to macadamia nuts.

Young Macadamia plant

Macadamia Nuts


© MMIV - Volume 1 Number 2 Whole Number 2  Tropical Visions

Spinning Macintosh apple