Genetic diversity in yeasts reshapes winemaking practices

Yeasts play a crucial role in the alcoholic fermentation process, transforming grape must into wine. There is significant genetic diversity among enological yeasts, with species in the winemaking environment covering a broad phylogenetic range. This diversity means that different strains of the same species can have varying impacts on fermentation and wine characteristics. Understanding the genetic determinants of these yeasts' physiological traits is essential for developing microbial biotechnology strategies to control fermentation and aging.

Saccharomyces cerevisiae is the most prominent enological yeast, dominating most spontaneous fermentations and being the sole industrial starter culture until the late 20th century. Recent articles explore the genetics and genomics of S. cerevisiae and other Saccharomyces species, highlighting the genetic diversity of important traits and practical aspects like strain identification and genetic improvement.

Since the early 21st century, enological biotechnology has seen a shift with the gradual introduction of alternative starter cultures to S. cerevisiae. These new starters are often species isolated from enological environments, primarily in spontaneous fermentations. Their development as starter cultures is due to extensive research on microbial ecology and the physiological characteristics of these species. These new starters are typically used alongside S. cerevisiae, as most cannot consume all the sugars in the must, potentially causing fermentation to stall. They are usually inoculated simultaneously with S. cerevisiae, but in a higher proportion, or one or two days earlier to ensure a significant impact on the process.

An example of this transition is a yeast species once considered a spoilage organism now used as a starter culture. Understanding spoilage yeasts is as crucial as knowing beneficial ones. Brettanomyces bruxellensis is a significant concern in the wine industry, causing economic losses, especially in wines aged for long periods. Traditional control methods are often ineffective against Brettanomyces. Understanding its genetic diversity is vital for improving prevention and correction processes.

The dossier provides technical, updated, and relevant information on the genetics of yeasts of interest in enology, whether as starter cultures or for their spoilage potential. The articles are written in accessible language by active researchers from prestigious institutions in Spain and South America, specializing in enological biotechnology.