Vanilla - A Plant Provide The Most Popular Flavour In The World

Botanical name: Vanilla Planifolia
Family: Orchidaceae (Orchid family)
Other names: flat leaved vanilla, vaniliya (Bulgarian), vanilla (Danish), vanilla (French), vanilla (hindi), banira (japan), vaniglia (Italy)

by Dr. Lalith Gunasekera

(May 17, Melbourne, Sri Lanka Guardian) Vanilla is an orchid, form a flowering plant genus about 150 species in the orchid family. Vanilla is the only orchid that produces an edible fruit, the largest family of flowering plants in the world. Vanilla is arguably the world’s most popular and sought after flavour. The sweet, fruity and floral characteristics coupled with the strong aroma, makes vanilla an outstanding flavour. Vanilla is the second most expensive spice after saffron due to the extensive labour required growing the vanilla seed pods.

Vanilla was originated in South East Mexico and Guatemala. The “Totonaca” people of Mexico were the first people to domesticate vanilla. They continue to cultivate the fruit that they consider was given to them by the god. Vanilla first left Mexico in the early 1500’s on ships bound for Spain. Until the late 19th century, Mexico had the monopoly on growing vanilla, but now Madagascar grows the majority of the world’s crop. Now it has spread to Costa Rica, Guatemala, Uganda, Turkey, Kenya, China, India, Sri Lanka, Indonesia, Tonga, Papua New Guinea, Tahiti, Hawaii and other Pacific Islands.

Vanilla grows best under hot humid climate from sea level to an elevation of 1500m. The ideal growing conditions are moderate rainfall, 150-300 cm, evenly distributed through 10 months of the year. The optimum temperature for cultivation is 15-300C during the day and 15-200C during the night. Ideal humidity is around 80%. The soils for vanilla cultivation should be loose with high organic matter and loamy texture. 

Growing vanilla is extremely labour intensive a delicate and inevitable expensive operation. Vanilla is a tropical, evergreen, leafy and somewhat fleshy vine, growing under a canopy of support trees. Stem can grow more than 35 m with alternative leaves spread along their length. The short, oblong dark green leaves of vanilla are thick and leathery. There are strong aerial roots grow from each node. Every year growers fold the higher parts of the plant downwards so that the plant stays at heights accessible by a standing human. This also stimulates flowering. It will take up to three years after the vine are planted before the first flower appear. The vanilla plant can produce up to 100 flowers on a single inflorescence but usually no more than 20. The flowers are quite large and attractive with white, green or cream colours. Most vanilla flowers have a sweet scent. Each flower opens up in the morning and closes late in the afternoon on the same day and never re-opens. If pollination has not occurred during that period, it will be shed. The flowers are self fertile but need pollinators to perform this task. The flowers can only be naturally pollinated by a specific “Melipona bee” found only in Mexico. But hand pollination is the most reliable method in commercially grown vanilla. Experienced pollinator can pollinate about 1000-2000 flowers in a day. This is labour intensive task.

The distinctive flavoured compounds are found in the fruit which results from the pollination of the flower. One flower produces one fruit. The fruit is termed “vanilla bean” (Pod). The fruit is technically an elongate, fleshy and dehiscent capsule 10 -20 cm long. The vanilla grows quickly on the vine but not ready for harvest until maturity – approximately 9 months in order to completely develop their signature aroma. However when the beans are harvested, they are still partially green and therefore have neither flavour nor fragrance. They develop these distinctive properties during the curing and drying process. Each bean ripens at its own time, requiring a daily harvest for 3-4 weeks. To ensure the finest flavour from every bean, each individual pod must be picked by hand just as it splits. It is crucial that the vanilla bean not be harvested until it is yellow on the tip and is beginning to split on the end. If picked too green the bean will lack flavour and develop moulds that will eventually cause it to rot. The fruit left on the plant, will ripen and open at the end, as it dries, the phenolic compounds crystallize, giving the beans a diamond –dusted appearance. The fruit contains tiny, flavourless seeds. 

Vanilla has 4 stages of production process. 

1. Harvesting: The pods are harvested at correct time

2. “killing” or inactivation of vegetative tissue: immediately wrapped and exposed to high heat and humidity to arrest further growth. This can be done by direct sun drying, hot water blanching, oven heating or freezing

3. Sweating/curing: pods are boiled and held at 45- 600C for 7-10 days in cloth covered boxes/containers immediately after boiling. This allows enzymes to process the compound in the pods into vanillin and other compounds important to the ultimate vanilla flavour. 

4. Drying/curing: The last phase is drying to prevent rotting and to lock the aroma in the vanilla beans. The beans are laid out in the sun during the mornings and returned to their boxes in the afternoon. This may take weeks. The cured vanilla beans have lost 60-70% of their moisture and will exhibit their fullest aromatic qualities.

Then pods are stored out and graded according to aroma, size and quality and particular market demands. Then they will rest for a month or two to finish developing their full flavour and fragrance. This process and manual pollination makes vanilla one of the most expensive spice in the world.

Like other orchid’s seeds, vanilla seed will not germinate without presence of certain fungi. Thus growers reproduce vanilla by cutting. Normally they remove sections of the vine with six or more leaf nodes, a root opposite each leaf. The two lower leaves are removed, and this area is buried in loose soil at the base of a support. The remaining upper roots will cling to the support, and often grow down into the soil. Rapid growth can be obtained under good conditions. An average of 2000 cuttings can be planted per hectare.

There are 3 main commercial preparations of natural vanilla:

1. Whole pod
2. Powder (ground pods, kept pure or blended with sugar or starch)
3. Extract (in alcoholic or occasionally glycerol solution)

Vanilla is used for food flavouring in baked goods, sodas, candies, syrups, ice cream, soy milk and perfumes and added to most chocolate industries.

Vanilla has always been an expensive commodity and many attempts have been made to create substitutes and synthetics. In fact 95-97%% of vanilla used as a flavour and fragrance is synthetic. A good synthetic duplicate of real vanilla simply does not exist. Most imitation vanillas contain “vanillin”, only one of 171 identified aromatic components of the real vanilla beans. Vanillin can be produced synthetically from lignin. Most synthetic vanillin is a by product of the pulp and paper industry and is made from waste sulphate which contains lignin sulfonic acid.

World production of processed vanilla beans average between 2000 -2400 metric tons per year. Madagascar is the largest producer with 1000 – 1200 metric tons per year, followed by Indonesia at 350 metric tons per year. The USA consumes well over half the world’s supply, followed by Europe, especially France. 

The dairy industry uses a large amount of the world’s vanilla in ice creams, yought (fresh and frozen) and other flavoured dairy products. Despite all the wonderful ice cream choices available in the market place, vanilla is still the most favourite flavour.

Growing vanilla is a good agricultural industry to promote in Sri Lanka. Mid country climatic condition is ideal for vanilla growth.