2018 ASVO Seminar; Fermentation- Converting research to reality


Wild wine: metagenomic analysis of microbial communities during wine fermentation Dr Anthony Borneman, The Australian Wine Research Institute
Wine is a complex beverage, comprising thousands of metabolites that are produced by yeasts and bacteria acting on grape must. To ensure a robust and reliable fermentation, most wines are produced by inoculating grapes with specific commercial strains of the wine yeast Saccharomyces cerevisiae. However, there is a growing trend back to the historical practice of performing uninoculated or ‘wild’ fermentations, in which only those yeasts and bacteria that are naturally associated with the grapes or winery are used. Wild ferments show a far more complex progression of microbial species than inoculated wines and, accordingly, a more complex taste and aroma profile. As such, differences in these resident microflora between vineyards and wineries are therefore thought to have a key role in defining regional expression of wine characteristics. In order to map the microflora of spontaneous fermentation, DNA sequencing (metagenomic) techniques are being used to monitor the progression of microbial species in large numbers of wild fermentations from across the major winemaking areas of Australia. Notable differences between regions, vineyards and wineries were apparent and these can be broadly defined by the resulting microbial composition of the wild ferments.