Sherry wine, Spanish-type

The Spanish sherry type of film yeasts tolerate high alcohol concentrations (up to 16 percent) and cause compositional and taste changes which are considered to be serious defects in nearly all wines except Spanish-type flor sherries. The most obvious compositional changes in... 

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. 

All sherries are improved by aging. The young baked sherries are strongly flavored and rough in taste. Oak chips are used commonly in competitive sherry types. The better wines are stored in fifty-gallon American oak barrels for several months to several years. American oak is favored because of the stronger aroma and drier taste of wines stored in it. The richness in flavor imparted by European oak apparently does not fit well into sherry flavors. It is interesting to note that American oak is favored also by Spanish winemakers. 

Sherry in english and german—Jerez in Spanish—Xeres in french is the best-known flor wine. In o/oro5o-type sherry, the aging process is essentially physicochemical and biological development is limited. The oloroso method will, however, be described in this section. Jura yellow wines are another well-known example of flor wines. 

---