Vodka drinkers often display a preference for one brand of vodka over another. Now, scientists have found the reason behind it.
Researchers are reporting the first identification of a chemical basis for people's preference for certain brands of vodka, which outsells rum, gin, whiskey, and tequila.
They found that vodka differs from simple water-ethanol solutions in ways that could alter vodka's perceived taste.
Dale Schaefer and colleagues, who conducted the study, note that vodka has a long-standing reputation as a colourless, tasteless solution of 40% pure ethyl alcohol, or ethanol, and 60% pure water. All such beverages should have the same faint or undetectable taste.
But sales of premium vodka brands have surged in recent years. Schaefer's group at the University of Cincinnati worked with colleagues from Moscow State University in Russia to find an answer.
They knew that famed Russian chemist Dmitri Mendeleev, noted for work on the Periodic Table of the Elements, made a key observation on alcohol solutions in his 1865 doctoral dissertation.
Mendeleev believed that a solution of 40% ethanol and 60% water would develop peculiar clusters of molecules, called hydrates. That solution became the global standard for vodka, which usually is sold as an 80-proof, or 40% alcohol, beverage.
A century later Nobel Prize-winning chemist Linus Pauling speculated that the hydrate clusters might consist of an ethanol molecule sequestered by a hydrogen-bonded framework of water molecules.
The scientists used high tech instruments to analyse the composition of five popular vodka brands. They found that each vodka brand differed in its concentration of ethanol hydrates. Vodka drinkers could express preference for a particular structure.
Drinkers actually may be perceiving this internal structure or structurability of vodka, rather than taste in a traditional sense.
The study has been published online in the Journal of Agricultural and Food Chemistry.
