According to legends of the indigenous Totonac people of Mexico, in a time before vanilla was cultivated, there once lived the beautiful princess Tzacopontziza of the Totonocopan kingdom. A young prince named Zkatan-Oxga saw her picking flowers for a temple offering one day. Overcome with passion, he whisked her away into the lush forest. But they were stopped by the temple priests and executed on the spot for their transgressions.
After several months, at the place where the two had been killed, the tendrils of a young, fragile green vine grew, reaching many feet tall in a few days. The vine bore green pods that released a fragrant scent when opened that perfumed the entire rainforest. And so, it was the death of the beautiful princess that brought us vanilla.
This myth of Tzacopontziza is one of many stories that riddle the oral histories about the origin of vanilla, but the Totonacas all agree that the vanilla pod fruit of the tlilxochitl vine was an incredible gift bestowed upon them. Tantalizing yet delicate, the flavor and aromas of vanilla were prized by the Totonac, who cultivated it for centuries. During the 15th century, though, the Aztecs conquered the region and forced the Totonacas to pay tribute with their vanilla pods. The Aztecs were fond of chocolatl, a predecessor to hot chocolate, and combined the vanilla with their cocoa beans. After the Spanish conquered the Aztecs and brought chocolatl back to Spain, the taste for vanilla expanded to Europe. Queen Elizabeth I’s royal apothecary, Hugh Morgan, transformed it from a chocolate additive to a flavoring in its own right, and vanilla became a court favorite.
The Birth of an Industrial Flavor
Once vanilla made its way into the Western world’s gustatory consciousness, its uses expanded exponentially. Demand for vanilla rose as it appeared in recipes for confections, pastries, beverages, candies, and ice cream, and it continues to be one of the most important flavoring agents in the world today. However, the places where a vanilla orchid can thrive are primarily the tropical regions that are often subject to rainstorms, deforestation, and fluctuating harvests: Mexico, Tahiti, the West Indies, and Madagascar. Vanilla harvesting methods are also labor intensive, requiring manual pollination of the flowers before fruiting and collecting mature pods every day because each pod ripens at its own pace. These factors together are largely responsible for the high cost of vanilla, making natural vanilla the second most expensive flavor in the world behind saffron.
This high cost created a push for alternative sources of vanilla flavor. In 1858, French pharmacist Nicolas-Theodore Gobley isolated pure vanillin crystals from vanilla bean extracts and determined vanillin was its principle flavor compound. Two enterprising German chemists, Ferdinand Tiemann and Wilhelm Haarmann, later deduced the chemical structure of vanillin, allowing them to manufacture the first synthesis of vanillin using coniferin, a product of pine tree sap and a readily available glucoside of isoeugenol.
With a new production process and lower price, uses for vanilla flavor spread like wildfire.
Together, they commercialized this process with a vanillin production plant but surprisingly did not have financial success. Within in a few short years, though, Tiemann and Karl Reimer devised a second synthesis of vanillin by subjecting guaiacol, a less expensive product of wood and coal pyrolysis, to the action of warm chloroform and alkali followed by the addition of strong acid. Now known as the Reimer-Tiemann reaction, the chemical synthesis was commercially successful and led to the formation of the Haarmann & Reimer Company, a corporate predecessor of the flavor powerhouse now known as Symrise.
With a new production process and lower price, uses for vanilla flavor spread like wildfire and sparked the mass production of treats, confections, baked goods, sweets, and drinks (alcoholic and otherwise) normally reserved for the wealthy upper class. At one point, vanilla made its way into ice cream, which was popularized in the United States by Thomas Jefferson.
Vanilla also found use in the perfume industry as a base note, where its unique ability to enhance sweet scents and round out stronger ones became an important feature, exemplified by Jacques Guerlain’s Shalimar perfume of 1925. The economy of vanilla also created a new opportunity for food entrepreneurs. In 1886, Coca-Cola arrived, and its original formula called for vanilla. The escalating demand meant the future of the vanilla enterprise seemed secure.
The Evolution of Synthetic Vanilla
The growing vanilla industry expanded efforts to develop new methods of vanillin synthesis and drive down costs. Clove oil’s main component, eugenol, was found to be structurally similar to coniferin, and its lower price made the method of synthesizing it to vanillin economical. This process fell out of favor by the 1920s, though, after the meteoric rise of the petrochemical industry made low-cost synthetic guaiacol available. In the 1970s, Solvay developed a more efficient pure petrochemical process of vanillin synthesis that’s still in current use where guaiacol is reacted with glyoxylic acid to form vanillylmandelic acid, which is acidified and oxidized by atmospheric oxygen to form vanillin.
Another method of vanilla production uses lignin as a substrate, an abundant biopolymer found in wood and a byproduct of wood processing. By oxidizing the lignin with caustic lye and sulfides, vanillin is easily synthesized. Unfortunately, the product is not approved for food use due to the toxic copper reagents used to affect the catalytic oxidation process. The vanillin produced this way is used mostly for perfumes and as a reagent in the production of pharmaceuticals.
Ethylvanillin, a minor byproduct of the guaiacol process, is another synthetic variant used since the 1930s that has a stronger flavor than vanillin itself and can withstand the high temperatures of baking. The vanillin molecule contains a one-carbon methyl-substituent, and replacing it with the two-carbon ethyl group gives ethylvanillin. It’s three to five times stronger in flavor intensity and much more expensive — typically reserved for high-quality chocolates and baked goods. But ethylvanillin and vanillin are synergistic, so they can be mixed to give a richer mimic of vanilla flavor.
The Vanilla of Today and Tomorrow
Currently, annual vanillin production reaches about 18,000 metric tons with 85% of the world’s vanillin produced using the guaiacol method and the remaining 15% made from lignin. Madagascar and Indonesia represent the largest contributors of natural vanilla with a combined output up to around 6,000 metric tons. Vanilla production continues to grow with expanding food markets with its incorporation into fabricated foods that require a pleasant, smooth, creamy-sweet aroma to round out the desired flavor. Indeed, the vanilla aroma is so unique and important in flavor formulation that it represents its own individual class within flavorist circles.
The current industry trend for food companies, driven by consumer demand for the all-natural label, has been to move away from synthetic vanillin. Several food companies, including Nestle, General Mills, Hershey’s, and Kellogg’s, have adopted natural vanilla for their products. The great challenge is the small global output of natural vanilla, leaving many flavor houses to contend with high prices and an uncertain supply. Flavorists and food producers have been forced to reformulate their products’ concentrations of vanillin.
A synthetic biology approach may become important in building a sustainable and reliable pipeline of natural vanilla.
Biotechnology companies Evolva and Ginkgo Bioworks are approaching the natural vanilla flavor challenge from another angle. Using gene-editing methods to introduce biosynthetic genes into yeast cells, they are producing vanillin by fermenting cheap and widely available sugar feedstocks.
Because the flavor compounds are produced by living organisms and not synthesized using chemical precursors, this vanillin could potentially be labeled as natural under current regulations. This synthetic biology approach may become important in building a sustainable and reliable pipeline of natural vanilla. However, consumer fears about genetically modified organisms such as this and their products may push these firms to redirect their efforts.