Abstract
The principal role of wine yeast is to transform efficiently the grape-berries’ sugars to ethanol, carbon dioxide, and other metabolites, without the production of off-flavors. Wine yeast strains are able to ferment musts, while other commercial or laboratory strains fail to do so. The genetic differences that characterize wine yeast strains in contrast to the biological ageing of the veil-forming yeasts in Sherry wines are poorly understood. Saccharomyces cerevisiae strains frequently exhibit rather specific phenotypic features needed for adaptation to a special environment, like fortified wines with ethanol up to 15% (v/v), known as Sherry wines. Factors that affect the correct development of the veil of flor during ageing are also reviewed, along with the related aspects of wine composition, biofilm formation processes, and yeast autolysis. This review highlights the importance of yeast ecology and yeast metabolic reactions in determining Sherry wine quality and the wealth of untapped indigenous microorganisms co-existing with the veil-forming yeast strains. It covers the complexity of the veil forming wine yeasts’ genetic features, and the genetic techniques often used in strain selection and monitoring during fermentation or biological ageing. Finally, the outlook for new insights to protect and to maintain the microbiota of the Sherry wines will be discussed.
Highlights
The Origin of Sherry WinesBiological ageing of wines is traditionally carried out in different regions, such as the wines ofJura (France), Szamorodni and Aszú (Tokaj-Hegyalja, Hungary) or Vernaccia di Oristano (Sardinia, Italy)
Studies on Spanish wine fermentations using restriction patterns generated from the PCR-amplified regions spanning the internal transcribed spacers (ITS 1 and 2) and the 5.8S rRNA gene demonstrated that flor yeasts which carry out the biological ageing in the Jerez-Xèrés Sherry and Montilla-Moriles D.O. showed a 24 bp deletion located in the ITS1 region [5,9,23]
Some studies [6] revealed that biochemical tests are necessary to identify and classify the different flor yeasts involved in Sherry wine, since each yeast strain might bring to the Sherry wines a different organoleptic characteristic
Summary
Biological ageing of wines is traditionally carried out in different regions, such as the wines of. Produce a “young” wine, and a biological ageing of this wine occurs by other veil-forming yeasts, Biologicalyeasts ageing, in turn, involves two phases: a static one (‘añadas’) during which the wine is the so-called of flor kept in a butt for a variable number of years, followed by aone dynamic phase known as “criaderasBiological ageing, in turn, involves two phases:. “soleraje”, consisting of a series of oak barrels of sherry in process of maturation divided kept in a butt for a variable number of years, followed by a dynamic phase known as “criaderas-solera”. 1–3 cm thick growing on the free surface of the wine (barrels “criaderas” (with a variable number of barrels) They have a common characteristic of a veil of flor of are up togrowing. Different properties of industrial interest have been detected, such as physiologic, genetic, and metabolic characteristics in the different identified strains, as well as clear differences using molecular analysis techniques [1,2,13,14,15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
