How is vanilla flavouring in wine possible?

Vanilla is one of the tertiary aromas, appearing when the wine is aged in new oak barrels. This note is the result of a subtle alliance between the wood fibers of certain oak varieties and the grapes fermented in contact with air. Under the influence of critic Robert Parker, an unconditional fan of new oak, many Bordeaux wines were marked by vanilla, sometimes to the point of excess.

Vanilla: the golden bean

The history of vanilla is associated with that of chocolate. The Aztecs, and before them the Mayans, added vanilla to their thick cocoa-based beverages. The Spaniards discovered this spice during the colonization of the Americas.

Vanilla is the fruit of certain tropical orchid species of Mesoamerican origin. Three varieties are cultivated for their fragrance:

• Vanilla Tahitensis from Tahiti,
• Vanilla Pompona from the West Indies
• and Vanilla Fragans, characteristic of the Bourbon appellation from the Comoros, Reunion and Madagascar.

Bourbon pods are spicy and slightly animalic, while those from Tahiti are more reminiscent of chocolate or dried fruit. While it has been possible to acclimatize the vanilla plant in different geographical areas, fertilization has proved a real challenge. In fact, natural fertilization of this flower requires the intervention of a bee specialized in orchid foraging and found exclusively in the dense forests of Central America. Any attempt to introduce the insect outside its place of origin has proved unsuccessful. The human hand is therefore needed to successfully fertilize the plant.

The cultivation and preparation of vanilla requires long and painstaking care, and the few climatic hazards that have reduced production and increased demand have made vanilla the most expensive spice in the world, behind saffron. The price per kilo easily reaches 600€.

Vanilla in wines

This aroma, particularly in red wines, is closely linked to the barrel and its heating level. A simple difference in temperature can switch to other aromas such as toasted almond, chocolate or coffee.

The amount of vanillin (the vanilla molecule) also depends on the variety of oak used to make the barrels. Few wines and grape varieties can withstand ageing in new barrels.

South-Western grape varieties are well represented in this category, with tannat, cabernet-sauvignon and merlot. Syrah and Pinot Noir are also well represented.

In the whites, chardonnay stands out. However, some white wines can naturally express vanilla aromas without having been aged in barrels, as in the case of Gaillac wines made with the mauzac grape.