vanillin , the naturally occurring phenolic aldehyde that gives vanilla beans their principal flavor, is used as a flavoring agent for many foodstuffs, usually in synthetic form; in spirits, however, it is a natural byproduct of barrel aging. It can be leached from raw oak, but the processes of barrel production (during which lignin and tannins are broken down by heat and fire) increases its availability in the wood. Vanillin is alcohol soluble and slightly water soluble and will slowly dissolve into the spirit as it ages, giving aged spirits some of their sweet and rich flavor notes. Over time, vanillin will react with the oxygen in the barrel; as it degrades, its breakdown products react with some of the other compounds in the spirit, adding more flavors.
See also barrel; charring, toasting (and recharring); maturation; and phenol.
Buxton, Ian, and Paul S. Hughes. The Science and Commerce of Whisky. London: RSC, 2015.
Esposito, Lawrence J., et al. Kirk-Othmer Encyclopedia of Chemical Technology, 4th ed. New York: John Wiley & Sons, 1997.
Jackson, Ronald. Wine Science: Principles and Applications, 4th ed. Amsterdam: Elsevier, 2014.
By: Doug Frost