Macadamia nuts are incredibly tough to crack, even if they've been boiled or roasted first. Typical nutcrackers won't do the trick, and less refined methods, like smashing them with a standard hammer, end up crushing the delicate nuts inside. Read on for two methods you can use to crack macadamia nuts.
STEPS
METHOD 1 OF 2: USE A VISE GRIP AND A HAMMER
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GATHER TOOLS. You can make a makeshift macadamia nut cracker with a vise grip, an iron bar to set the nut against, and a flat hammer.[
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Vise grips are common tools available at any hardware store. If you love macadamia nuts and plan to shell them often, it's worth buying a vise grip for this specific purpose (though you'll probably find other uses for it as well).
Be sure the hammer has a flat end, rather than a round one. You'll need to exert force evenly on the nutshells.
If you don't have an iron bar, any tough, metal surface will do. Other hard surfaces like marble, glass, concrete or wood could get damaged by the pounding, so make sure you're working over metal.
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GRASP THE NUT IN THE VISE. Lie it up so that the seam of the nut is facing upward, rather than against the inside of the vise. Set the vise to grip it tightly.
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PLACE THE GRIPPED NUT AGAINST THE METAL BAR. Hold the vise handles tightly and make sure you've got a good grip, since you don't want the nut to slip when you bring the hammer down.
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POUND THE NUT WITH THE HAMMER. Try to hit it square on the seam so that it cracks cleanly. Let the hammer bounce back toward you as the nut cracks open.[2]
You may have to try this a couple of times before you learn exactly how much force to exert.
Letting the hammer bounce or pull back slightly is important, since it keeps the hammer from smashing the nut inside.
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RELEASE THE NUT FROM THE VISE. The shell will fall away, and the intact nut is now ready to be popped into your mouth or used in a recipe.
METHOD 2 OF 2: USE A HOLE IN A ROCK
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FIND A ROCK WITH A HOLE IN IT. This method originated in Hawaii, and is still commonly used there to crack into macadamias. The rock provides a hard surface to stabilize the nut. Look for a small hole that's deep enough to hold the nut in place, but shallow enough so that it sticks out over the hole a bit.
If you live near volcanic rock, you'll likely find some with holes just the right size.
If you don't live near volcanic rock, locate some limestone or shale with natural, small holes in it. Some people have found success using a crack in the sidewalk; be careful, though, since you could damage the sidewalk with this method.
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SET THE ROCK IN THE HOLE SEAM-SIDE UP. Carefully place it so that the seam is facing up and you'll have a clear shot when you pound the shell open.
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POUND THE NUT WITH A ROCK. Any heavy, flat, hard rock should work. Grasp the rock tightly, lift it over your head, then smash it down on the seam of the macadamia nut shell. The shell should pop right open.
Let the rock bounce back toward you slightly after you pound it down. If you continue driving it into the shell you'll smash the nut inside.
If you have trouble breaking open the shell, experiment with different angles and rocks of different shapes and sizes.
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EXTRACT THE NUT. Take a look at the nut to make sure it doesn't have gravel or other rock particles attached to it. You may want to rinse it off before consuming.
TIPS
Pre-shelled nuts are never as good as nuts straight from the shell, as the nut oils begin to go rancid on contact with the air. Preserve your uneaten cracked nuts in the refrigerator for up to a week after cracking. Only crack the amount you are likely to need to avoid wastage.
Cracked macadamia nut shells are said to be great for garden mulch.
Be careful of the shards from the shell. They tend to fly everywhere when the hammer comes down. Best done in an area where the mess can be easily swept up, or cover a large area with newspaper that you can easily collect up and throw away afterwards.
Some say that macadamia nuts that have been placed in the freezer an hour before cracking are much easier to crack.
WARNINGS
Watch your thumb and fingers - keep them away from the area that the hammer is set to come down on.
