Growth and Production
The cashew nut, while native to Brazil, is now commonly cultivated in 32 countries around the world.
They are very sensitive to frost, moisture and cooler climates; they can’t even tolerate California, thus they are not grown in the USA.
The traditional cashew tree can grow up to fourteen metres tall; however, a new breed of dwarf cashew tree grows only six metres tall and starts producing after one year instead of the average three years, with economic yield occurring after three and six years respectively.
The average annual yield for one cashew tree is about 0.25 metric tons while the dwarf variety can product over one metric ton per tree! The modern agricultural grafting techniques that helped create the dwarf cashew tree not only make the nut more economically sound for countries that typically experience financial hardship, but by being able to meet an ever-increasing global demand for product, more and more jobs are created.
Cashew trees are self-pollinating, leaning on the activity of ants, bees, flies and other insects to cross-pollinate within the orchard.
The cashew nut is a very labour-intensive product. The tree is quite easy to grow and they have few natural predators, meaning chemical intervention is almost non-existent. However, cashew farmers do not use irrigation methods and are dependent on the rain.
Tropical weather fluctuations can have a detrimental effect on cashew harvest if there is simply too little or too much rain, or if the rain arrives at the wrong stage in the tree’s growth.
Contributing to the hardships of harvesting the cashew is their corrosiveness. The nut grows at the bottom of what is known as the cashew apple. The apple itself is edible and is sweet and astringent: it has a short shelf life and isn’t typically exported.
If you travel to Brazil, Vietnam or one of the many producing countries, be sure to sample some of the products made from the cashew apple. Jams, juices and a variety of alcohol are examples of the tasty treats one may be able to try.
The nut itself is perhaps the only nut in the world that cannot be consumed raw from the tree. Each nut has a double shell that contains an allergenic resin known as anacardic acid, a potent skin irritant that is chemically similar to the urushiol oils found in poison ivy.
The black resin is toxic and will cause extreme intestinal pain, and can be fatal in some people. Cashew farm workers must wear protective clothing and cover their arms and hands to prevent their skin from coming in contact with the caustic black resin found inside the hull.
During processing the hulls are manually shelled, the kernel extracted and set aside to have the resin removed in a steam bath. In some cases, a cashew farm will use the hulls to fuel the steam cauldrons, making it a complete and relatively waste-free system. However, the hulls are often more valuable when converted into diesel fuel, and the farms will burn cheaper wood to complete the processing. Once the cashews have been steamed, the brown skins that protect the nut from the resin are painstakingly and manually removed by farm labourers, by hand and nut by nut.
Laid out in the hot, tropical sun for drying is the last step these creamy nuts undergo before being distributed for further processing, roasting or direct sale.
So when you see “raw” cashews at the supermarket, it means the nut has only undergone surface steam processing, similar to one of the almond pasteurization techniques, to remove the resin and have not been roasted.
History and Usage
The cashew nut isn’t considered a historically rich crop like the almond and doesn’t make an appearance in the Bible or on the Silk Road trade routes. It was introduced to India by the Portuguese nearly 500 years ago where it was brought to the world market and processing techniques were pioneered. From there crops spread to other tropical countries such as Vietnam, Tanzania and Nigeria.
Even though the cashew nut cannot grow in the United States, it doesn’t mean it isn’t appreciated in our neck of the woods. The USA is the biggest importer of cashews with an annual importation of over 50% of the world’s cashew exports.
Cashews are eaten raw, roasted and salted; they’re common in trail mixes and are often used to top off savoury dishes. They are a valuable ingredient for raw and vegan diets, and can easily be made into a great dairy alternative. The high starch content is useful as a thickener for sauces, soups and some desserts, and it is found to be one of the creamier and more delicately flavoured nuts available.
“Cashew nut shell liquid” (CNSL) is the term given to the toxic resin. Another step in making cashew farming a complete system is the versatility and value attributed to the liquid itself. There are innumerable uses for the resin and it can be found in brake systems, paint manufacture, pharmaceutical development, antioxidants, fungicides and anti-termite treatment. Some epoxy resins and surfactants are made from CNSL as well.
South American natives use the cashew nut shell oil as treatment for scurvy, warts, sores, ringworm and psoriasis, and as corrosive as it is, it is found to have potent antibacterial properties.
In addition to all of the industrial uses for the resin and the culinary uses for the kernel, the cashew solidified its place in the traditions of Ayurvedic medicine. Practitioners of the ancient Indian folk medicine use the nut as a stimulant, an appetite suppressant, a hair tonic and an aphrodisiac, believing it can restore lost vigour and sexual health.
Nutritionally, cashews are packed with health benefits. Like most nuts, they have a high fat content, though it is comparatively low to their counterparts. Cashew oil is comprised primarily of heart-healthy monounsaturated fats ~ similar to olive oil. They contain micronutrients like calcium and magnesium, which both contribute to overall bone health. Insufficient magnesium intake can lead to fatigue, high blood pressure, migraine headaches and muscle spasms.
Cashews are quite low on the glycemic index, making them a great snack for diabetics, helping to manage insulin and blood glucose levels, and decrease the risk for heart disease. Adding a handful of cashews to your daily diet can really stack up in your favour! Try this super straightforward Cashew Gravy as a delicious addition to any meal.