Macadamia Nuts are Coming In
Not many harvest managers have to deal with macadamia nuts, at least not in the contiguous 48 states. Our Hawaiian friends might be the exception. The Gardener, being the omni-planter that he is, nurtures a large and prolific nut tree in our back yard orchard. Last year the crop was stolen by some unidentified culprit thought to be a rodent of some kind. Not this year. The Gardener delivers nuts by the bucket. Happily, he actively participates in harvest management. The steps are simple but labor intensive.

Nuts still in the husk (top left), discarded husks in the compost bin (top right), and nuts in the shell ready to go to through the second drying (bottom).
First, dry the nuts long enough to split the husk so it can be removed from around the shell. This takes about 24 hours on medium heat in the dehydrator. Then, break off the husk and return the nut (still in its shell) to the dryer for another 24-36 hours. Now they are ready to store, or crack and eat.
Macadamia nut shells are notoriously hard calling for creative cracking techniques or an industrial strength nut cracker. The Gardener opts for the latter.
As he says, ‘one should use the right tool for the job’. Cracking macadamia nuts is a loud undertaking, as the shell makes quite a sharp crack when it gives way. The end result, however, is worth it.
I’ve tried to crack open Macadamias before and it’s difficult. Guess I didn’t use the right tool! Thanks for the explanation and pix.
The low tech approach to cracking a macadamia is to use a hammer. Find a way to stabilize the nut so it won’t roll away, then whack it. I good choice is a divot in a rock. The risk lies in hitting it too hard and smashing the nut meat. HowTo gives some nice options with pictures. http://www.wikihow.com/Crack-Macadamia-Nuts