Brazil nuts are grown on wild trees (Bertholletia excelsa) in the large tropical region of South America between Mexico and Brazil, which includes the Amazon region. The nuts have been an important food source of the indigenous people for centuries. Today they are also a source of income for the locals and a low impact alternative to the slash and burn method of farming. About 40,000 tons of nuts are collected annually and most are exported to North, South America, and Europe. Most nuts are collected from wild trees since attempts to develop tree plantations have not been successful.
The Brazil nut trees grow in clusters in the rain forest. They can grow to be several hundred feet tall and live to be hundreds of years old. The trees produce flowers between the dry and wet seasons. These large flowers open for only a few hours early in the morning and can only be pollinated by the female of a specific species of bee (Euglossa spp) that is both large and strong enough to enter the flower. These bees are only found in certain areas of the rain forest, which is why it has been so difficult to create Brazil nut tree orchards. Once pollinated the flowers slowly develop into woody "fruits". These fruits are roughly the size of a grapefruit and weigh about 5 pounds. Mature trees can produce about 300 of these fruits per season.
The fruits take 15 months to fully ripen and are harvested during the next wet season. Ripe fruits naturally fall to the ground and are so strong that they do not split open. Only a specific type of rodent called agouti (Dasyprocta) is able to gnaw into the fruit and spread the seeds by burying them. Harvesting the fruits can be hazardous, as the heavy fruits can fall several hundred feet before hitting the ground. Some fruits can make such a loud thud upon impact that the noise has been likened to a dropped cannonball! Once collected the fruits are cracked open to reveal between 10 to 25 Brazil nuts. The nuts have a rough, thick, brown shell. The shell and the nutmeat inside are three-sided and one to two inches long.
Brazil nuts are about 70% fat, however most of these fats are healthy omega-3 fatty acids. The nuts are so fatty that they can apparently burn like a candle if they are lit on fire. Brazil nut oil is commonly used by tribes in the Amazon for cooking and as a lighting source. The oil can also be purchased in both North and South America for cooking and as an ingredient in shampoos, hair conditioners, and massage oils. Brazil nuts also have the highest natural source of selenium. Selenium is a trace mineral that is thought to be an antioxidant and help ward off various cancers, especially prostate cancer.
Brazil nuts are very similar to macadamia nuts because they both contain such a high amount of fat. The two nuts can substitute for each other in recipes. Brazil nuts are sweet and rich and have a mild flavor somewhat like coconut. They make good snacks and are even better if they are first dipped in chocolate. Like other nuts, they can be used in a large variety of dishes, including baked goods, stuffings, and salads.
http://www.nybg.org/bsci/braznut/
http://www.rain-tree.com/brazilnu.htm
http://www.amazonconservation.org/home/brazilnuts.html
http://www.szgdocent.org/ff/f-bnut.htm