Ever wonder why you never see cashews in their shells? You can find just about any other nuts — from almonds to walnuts — in their shells, but not cashews. There’s a good reason for that.First, a bit of cashew background: Cashews are closely related to mangoes and pistachios. India and Brazil account for about 80 percent of the world’s supply of cashews, with Africa a distant third and Asia growing a smattering of the nuts.
The cashew itself consists of the “cashew apple” (which looks like a pear — go figure) and the cashew nut, a kidney bean-shaped appendage that grows at the end of the fruit. When the apple is ripe, it falls to the ground, and is gathered by natives who then separate the nut and the fruit. The locals enjoy the fruit, but it’s not commercially viable since it spoils within 24 hours.
The grayish-brown nut shell is about 1 1/2″ long; the nut inside grows on the end closest to the fruit, and inside the other end of the shell are honeycombed cells that contain a toxic resinous fluid called cardol. Besides mangoes and pistachios, cashews are also related to poison ivy and poison oak, and the cardol causes blistering and rashes just like those dreaded plants. In fact, the cashew was once known as the blister nut.
Removing the nut from the shell is a complicated procedure. The nuts are washed in water baths and stored for awhile until the shells become brittle. The older method for removing the nuts from the shells was to roast the whole nuts in shallow pans that were constantly agitated over charcoal fire. Unfortunately, this caused the shells to burst, releasing toxic fluid and acrid fumes and blistering the workers’ skin.
Modern extraction methods involve roasting cylinders that collect the fluid separately from the nuts. However, the shells still have to be cracked manually in small batches, using wooden mallets to avoid breaking the nut kernels. After that, the nuts can be roasted and/or salted or sold “raw.”
So next time you pick out all the cashews from a bowl of mixed nuts, leaving the lowly peanuts and Brazil nuts for everyone else, think about all those workers, risking their complexions and hammering their nuts just for you.
This article appears in Sep 22-28, 2004.
