show Abstracthide AbstractHumans have been consuming wines for more than 7,000 years. For most of this time, the fermentation was performed by strains of S. cerevisiae that naturally found their way into the fermenting must. However, most commercial wines are now produced by inoculation with pure yeast strains, ensuring consistent, reliable and reproducible fermentations and there are hundreds of yeast starter cultures that are now commercially available. In order to thoroughly investigate the genetic diversity that has been captured by over 50 years of commercial wine yeast development, whole genome sequencing has been performed on 212 strains of S. cerevisiae, including 119 commercial wine and brewing starter strains. Comparative genomic analysis has shown that, despite their large numbers, commercial strains, and wine strains in general, remain genetically similar, with high levels of apparent in-breeding. In addition, many commercial strains have near-identical counterparts, from multiple suppliers, suggesting that the limits of effective “industrial” variation within this group may me approaching saturation.