Sherry Wines: Worldwide Production, Chemical Composition and Screening Conception for Flor Yeasts

Abstract

The manufacturing of sherry wines is a unique, carefully regulated process, from harvesting to quality control of the finished product, involving dynamic biological aging in a “criadera-solera” system or some other techniques. Specialized “flor” strains of the yeast Saccharomyces cerevisiae play the central role in the sherry manufacturing process. As a result, sherry wines have a characteristic and unique chemical composition that determines their organoleptic properties (such as color, odor, and taste) and distinguishes them from all other types of wine. The use of modern methods of genetics and biotechnology contributes to a deep understanding of the microbiology of sherry production and allows us to define a new methodology for breeding valuable flor strains. This review discusses the main sherry-producing regions and the chemical composition of sherry wines, as well as genetic, oenological, and other selective markers for flor strains that can be used for screening novel candidates that are promising for sherry production among environmental isolates.

The Fingerprint of Fortified Wines – From the Sui Generis Pro-duction Processes to the Distinctive Aroma

“…Sherry is also protected by a layer of yeast called "flor", which gives the wine its distinctive nutty flavour. Sherry comes in a range of styles, from the dry and light Fino, Amontillado and Oloroso, to the sweet and dark Pedro Ximénez [4,29]. Produced in the southern region of Andalusia, Malaga is made from several grape varieties, including Pedro Ximénez and Moscatel [30].…”

“…The sherry brand of wine is traditionally made from white grapes that are grown near the city of Jerez de la Frontera in Andalusia (the south of Spain) [29]. This is an eminent wine-producing region located in the south of Spain, surrounded by mountains and coastal lands that condition the climate in the area, which together with its ageing methods, are determinant to attaining the highly desirable organoleptic characteristics of its oenological products.…”

“…This is an eminent wine-producing region located in the south of Spain, surrounded by mountains and coastal lands that condition the climate in the area, which together with its ageing methods, are determinant to attaining the highly desirable organoleptic characteristics of its oenological products. However, the maturation of sherry wines until recently was limited to the so-called "sherry triangle", that is, the three cities: Jerez de la Frontera, Sanlúcar de Barrameda and El Puerto de Santa Maria [29]. Sherry wines are considered among the most highly appreciated products in the world of oenology [4].…”

“…Sherry is aged using a solera system, in which wines from different vintages are blended to create a consistent flavour profile [5]. A unique feature of sherry strains of S. cerevisiae, in comparison with other fermentation strains, is their ability to form a biofilm (or flor) on the surface of alcoholic wine material, in which ethanol is oxidized to acetaldehyde under the action of alcohol dehydrogenase [29].…”

The Fingerprint of Fortified Wines—From the Sui Generis Production Processes to the Distinctive Aroma

“…Sherry is also protected by a layer of yeast called “flor”, which gives the wine its distinctive nutty flavour. Sherry comes in a range of styles, from the dry and light Fino, Amontillado, and Oloroso to the sweet and dark Pedro Ximénez [ 4 , 29 ]. Produced in the southern region of Andalusia, Málaga is made from several grape varieties, including Pedro Ximénez and Moscatel [ 30 ].…”