More than any other plants orchids are evocative of the exotic. In fact as a family the orchids are highly cosmopolitan, occurring almost everywhere on earth. With more than 20,000 species it is the largest family of flowering plants. In temperate regions most orchids are ground dwelling perennial herbs, however the majority of orchids live in the tops of tropical trees, some are climbers and others devoid of green pigments live like fungi obtaining nourishment from decaying matter. In spite of this vast diversity very few orchids have ever been domesticated, and the vanilla orchid is often said to be the only species of direct economic importance. However, this neglects the immensely important horticultural trade in ornamental orchids.
The name orchid is derived from the Greek word for testicle; the paired root-tubers of many temperate orchids resemble the male genitals. One of the tubers being last year’s growth is old and withered and the second being the current year’s is fresh and full. It is no great surprise therefore to find that orchid tubers have a long association with sexual superstitions. Witches were said to use the fresh tubers in producing potions of true love, while utilising the withered ones for spells of a more carnal nature. The herbalist Culpepper wrote that orchid roots ‘provoke venery, strengthen the genital parts and help conception’.
Although the vanilla orchid is now the only orchid regularly consumed by man, this has not always been the case. Until the rise of the coffee shop, the streets of London were full of salopian shops, purveying salep, which was a kind of nutritious starchy soup made from the roots of various orchids. It was said to be the ideal breakfast for chimney sweeps, who were able to purchase a basin of salep in Fleet Street for three-half pence. Herbalists compared the virtues of the salep derived from our different native orchids. It is strange to think that these now rare plants were once turned into something as mundane as a bowl of soup.
Today there are three species of orchids cultivated for vanilla. The Tahitian vanilla, which is grown in French Polynesia and Hawaii, is used almost entirely in the perfume industry. A second species, the West Indian vanilla produces Pompona vanilla, which has a fragrance reminiscent of cherries. Its active constituent, heliotropin is used in soaps, perfumes and to flavour tobacco, it is also occasionally blended with true vanilla.
The true vanilla orchid is a native of Central America where it was used by the Aztecs of Mexico to flavour cocoa. In 1520 the Spanish Conquistador Cortés was given some of this drink flavoured with chocolate and vanilla by Montezuma. This was Europe’s first taste of vanilla, within a decade dried pods were being exported to Spain. The vanilla plant is a scrambling vine, which can grow to 15 m tall. It has spectacular pale yellow flowers, which measure about 10 cm across. The flowers are constructed in such a way that the male and female organs are kept apart, physically preventing self-pollination. In its native Central America vanilla flowers are pollinated by bees and humming birds. The seed pods which subsequently develop are refereed to as beans, although the seeds they contain like the seeds of all orchids are dust like, measuring less than half a millimetre across. It is these seed pods which are harvested as the source of vanilla.
Most of the world’s vanilla is now grown on tropical islands such as Madagascar, Mauritius, Réunion and Tonga. However, when it was first introduced to these far-flung shores it failed to produce any vanilla beans and was entirely propagated by cuttings. The problem was simple, far from home vanilla was unable to pull the birds or attract the local bees. With no interest in the birds and bees, vanilla endured almost 50 years of sexual inactivity on the island of Réunion. It was not until 1841 that former slave Edmond Albius managed to ease the vanilla’s sexual frustration by manual means. Using a bamboo splint to replace the humming bird, a reliable method of artificially pollinating the vanilla flower was developed. Most of the world’s vanilla is now produced in this fashion.
About eight months after pollination the pods are ready for harvesting and curing. This is a complex process of drying in which the pods are spread in the sun for a few hours each day and then wrapped in blankets and stored in air tight containers to sweat over night. After two weeks of this treatment the beans turn black and are then dried off in the sun for two months. Finally the beans develop their full aroma in conditioning bins. The whole procedure takes about six months. This is why vanilla is so costly being the second most expensive spice behind saffron.
The elaborate curing process results in dried beans which contain less than three percent vanillin, which is a relatively simple chemical with the formula C8H8O3 that is responsible for the vanilla taste. Synthetic vanillin was first produced from the sap of pine trees in 1874. Since then vanillin has been manufactured from lignin, a waste product of the paper industry, 5g of artificial vanilla has approximately the same strength flavour as a litre of natural vanilla extract and costs about one hundredth of the price. But then as you pour it over your rhubarb, it does not evoke images of beautiful orchids growing on Tropical Islands.