Fino sherry aroma

The wine yeast, Saccharomyces fermentati, is able to form a film or veil on the surface of dry white wines of about 15-16% alcohol. This yeast produces agreeable smelling and tasting substances which dissolve in the wine and give it the aroma and flavor characteristic of Spanish fino sherries. To provide itself with energy for growth while in the film form on the surface of the wine, the yeast utilizes some of the oxygen from the atmosphere above the wine in the partially filled butt or barrel to oxidize some of the ethyl alcohol from the wine. The ethyl alcohol of the wine is not completely metabolized to carbon dioxide and water, however, but is oxidized to acetaldehyde—probably the principal compound in the complex mixture responsible for the aroma of this type of appetizer wine. 

Martinez, P., Valcarcel, M. J., Perez, L., and Benitez, T. (1998). Metabolism of Saccharomyces cerevisiae flor yeast during fermentation and biological aging of fino sherry By-products and aroma compounds. Am. J. Enol. Vitic. 49, 240-250. 

Zea, L., Moyano, L., Moreno, J., and Medina, M. (2007). Aroma series as fingerprints for biological aging in fino sherry-type wines.. Sci. Food Agric. 87, 2319-2326. 

Webb and Noble (12) reported on the aroma constituents of the four general types of sherry. Fino, oloroso, submerged culture, and baked sherries have significant differences in aroma constituents. Many constituents were identified, but much more research is needed to correlate volatile components with sensory perceptions. 

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