Vanilla

Vanilla planifolia is a perennial climbing orchid with thick, fleshy stems and aerial roots that attach to trees or supports. Its pale greenish-yellow flowers open for only a single morning, and each flower must be pollinated within hours. Fertilised flowers develop into slender green pods, 15 to 25 centimetres long, each filled with tens of thousands of tiny black seeds suspended in an oily, aromatic paste. After harvest the pods are cured for weeks, through heating, sweating and drying, which develops the vanillin and other flavour compounds and turns them dark brown and supple.

Vanilla planifolia is native to southeastern Mexico and Central America, where it grows as a forest vine. Mexico's Totonac people are said to have been among the first to cultivate it. Today, Madagascar is the leading producer, followed by Indonesia and other countries such as Uganda, Papua New Guinea, Mexico, Tahiti and the Comoros and Réunion islands. Other species are also grown, including Vanilla tahitensis, the Tahitian vanilla, and Vanilla pompona. Natural pollination in Mexico depends on specific native bees, so elsewhere it is done by hand.

Pre-Columbian peoples used vanilla to flavour cocoa drinks, and the Aztecs adopted the practice after conquering the Totonac. Spanish explorers brought it to Europe in the sixteenth century, where it became a luxury flavouring, first for chocolate and later for confectionery and desserts. For three centuries vanilla vines taken elsewhere flowered but did not set fruit, because the native pollinators were absent, and Mexico held the monopoly.

That changed in 1841, when Edmond Albius, a twelve-year-old enslaved boy on the island of Réunion, devised a quick method of hand-pollinating the flowers with a thin stick and thumb. The technique is still used worldwide, and it allowed vanilla farming to spread to Madagascar and across the tropics. Synthetic vanillin, first made in the nineteenth century, now supplies most commercial vanilla flavour, but natural vanilla remains valued for its complexity and commands high prices.

Whole pods are split and the seeds scraped into custards, ice cream, cakes, sauces and drinks, and the empty pods are steeped in milk or sugar. Extract, made by soaking pods in alcohol and water, is the most common form, along with vanilla paste, powder and whole-bean sugar. Vanilla enhances sweet dishes and is also used in savoury cooking with seafood, such as scallops and lobster, in sauces and in perfumes and cosmetics.

Vanilla is used in tiny quantities, so its direct nutritional contribution is negligible. The characteristic aroma comes mainly from vanillin, along with hundreds of other volatile compounds. Vanilla's flavour can make foods taste sweeter, which may help people reduce the sugar they add to recipes, though research on this is limited. Pure extract contains alcohol, roughly 35 percent by volume under common standards, though the amount per serving is small. Claims about medicinal effects are not well established.