The cashew tree is an evergreen native to northeastern Brazil, but it can be found in tropical climates in many parts of the world. The tree can grow as high as 14m, but there are also ‘dwarf’ varieties that generally grow to about 6m in height. Cashew trees produce an ‘apple’ and a seed. The seed is attached to and grows from the ‘apple.’ It contains the nut that most people think of when they think of eating cashews.
Cashew trees were originally brought from Brazil to India by the Portuguese in the mid-1500s. From there cultivation spread to many parts of Africa and Southeast Asia. Today, India, Brazil, Vietnam and regions of West Africa are some of the major producers of cashew nuts for the global market.
Cashew nut production has expanded rapidly in Cambodia over the last two decades, but because of the difficulties associated with processing cashews for human consumption (see “When Can I Eat Them?”) most raw cashews grown in the country are exported to Thailand or Vietnam for processing.
When Can I Eat Them?
Cashew nut trees fruit once a year, usually in late spring in the northern hemisphere. In Cambodia the cashew nut harvest usually happens from February / March to May. Cashew seeds are considered ripe when the ‘apple’ to which they are attached changes color from green to red or yellow. Raw, unshelled cashew seeds can be stored for an extended period of time.
Processing cashew nuts for human consumption is, however, a somewhat complicated process. The interior of the cashew nut shell/seed contains a kind of oil that can irritate human skin. Exposure to this oil can produce effects similar poision ivy. The outer shell must be removed in such a way to avoid the effects of this oil. The nuts are then roasted and prepared for consumption. The nuts can be eaten whole as a snack. They are also incorporated into a variety of dishes. Cashew nuts can also be used to produce cashew nut butter and cashew nut milk.
Although the cashew ‘apple’ is often discarded during the harvesting process it can be converted into a fruit juice or distilled and fermented into an alcoholic beverage. Efforts to increase the production of cashew ‘apple’ juice have grown in recent years.
What To Look Out For?
Although the oil that’s contained inside cashew nut shells can irritate human skin it is perfectly safe to handle raw, unshelled cashew nuts. Some people also experience allergic reactions with consuming cashews.
In Khmer cooking cashew nuts are incorporated into a variety of dishes and sweets.
Here’s a link to the Wikipedia page on cashew trees: https://en.m.wikipedia.org/wiki/Cashew