Cashew Nuts in Raw and Processed Form

Description

The cashew tree is a tropical evergreen tree that produces the cashew seed and the cashew apple. It can grow as high as 14 m, but the dwarf cashew, growing up to 6 metres, has proved more profitable, with earlier maturity and higher yields.
The true fruit of the cashew tree is a kidney or boxing-glove shaped drupe that grows at the end of the cashew apple. The drupe develops first on the tree, and then the pedicel expands to become the cashew apple. Within the true fruit is a single seed, which is often considered a nut, in the culinary sense. The seed is surrounded by a double shell containing an allergenic phenolic resin, anacardic  acid, a potent skin irritant chemically related to the better-known allergenic oil urushiol which is also a toxin found in the related poison ivy. Properly roasting cashews destroys the toxin, but it must be done outdoors as the smoke (not unlike that from burning poison ivy) contains urushiol droplets which can cause severe, sometimes life-threatening, reactions by irritating the lungs.