(Newsobserver) - Sequencing the genomes of hundreds of strains of the wine yeast S. cerevisiae has revealed little genetic diversity and high levels of inbreeding. In many cases, yeast strains sold by different companies were almost genetically identical. The results, published in the April issue of G3: Genes|Genomes|Genetics, suggest winemakers attempting to develop improved wine yeasts will need to look to creating hybrids with more exotic strains.

“Our results show that only a limited branch of the yeast evolutionary tree is currently used in winemaking,” said lead author Anthony Borneman of the Australian Wine Research Institute.

Yeast contributes to the flavors of wine and may even provide a component of a wine’s “terroir” – the local conditions that give a wine its unique flavor. Traditionally, wine has been fermented by naturally occurring yeast, but this can deliver inconsistent results from vintage to vintage. To yield more predictable results, most winemakers use pure active dried yeast starter strains that have been produced by commercial suppliers.