Update on the role of Saccharomyces cerevisiae in Sherry wines

Abstract

Sherry wines undergo a complex, two-stage production process. Initially, the Palomino Fino grape must undergo alcoholic fermentation, resulting in the base wine. This wine is fortified and enters the dynamic biological aging system known as “criaderas y soleras.” Despite the wide variety of wine yeasts available, there’s growing interest in developing new yeast strains with specific traits to enhance wine quality, safety, and consumer acceptance. Rising temperatures are expected to impact alcoholic fermentation stability and flor yeast film development during biological aging, potentially reducing wine quality. This chapter explores oenological advancements, such as reducing hydrogen sulfide and ethyl carbamate concentrations in Jerez’s base wines. Non-genetic modification techniques that enhance sensory complexity in industrial-scale winemaking are discussed. Additionally, a diverse range of yeasts, including Saccharomyces cerevisiae species with novel phenotypic traits, is found during biological aging, offering potential value in winemaking and biotechnology. The presence of mycoviruses in flor yeasts of the Saccharomyces genus, providing evolutionary advantages in dominance and establishment in “Fino” and “Manzanilla” wines, is examined. The chapter also delves into how these yeasts affect flor yeast film stability under varying temperatures and ethanol conditions, and alternative methods for veil of regeneration using amino acids as nitrogen sources or inert supports are explored.