Wine yeasts, the tiny stars of the winemaking process, play a fundamental role in the transformation of simple grapes into the complex elixir we know as wine. In this detailed journey, we’ll explore what exactly these microorganisms are and how they influence the production and origin of wine. What’s more, as experts in the sector, we’ll answer key questions on their presence in grapes and their enological selection.
What are grape yeasts?
First of all, we should explain what yeast is, as it is essential in transforming grapes to wine and cava. In fact, its capacity to convert sugars to alcohol is the central basis of the process of alcoholic fermentation, vital in the production of wine.
As such, whether through the natural action present in the different grapes varieties or with enological selection, wine yeasts are silent masters that bring complexity and character to the final drink. Understanding their role allows us professionals to influence the unique characteristics of each wine that reaches your glasses.
More specifically, wine yeasts are unicellular microorganisms belonging to the Fungi kingdom, and specifically the genus Saccharomyces. These small, magical spheres have the unique ability to convert the sugars present in the grape into alcohol and carbon dioxide through alcoholic fermentation. This way, their presence in the grapes kicks off the process that transforms the simple fruit into the complex and well-loved drink that is wine.
Where is grape yeast found?
Wine yeasts are mainly found in the skin of the grapes. This strategic location allows them to come into contact with the must when the grapes are pressed during the winemaking process. While the grapes ripen on the vine, the yeasts adhere to the skin, patiently waiting to trigger fermentation. This natural process, driven by the presence of yeasts in the wine’s must, is the first act in the theatre of winemaking.
Which yeasts are involved?
In the world of wine, various strains of yeast exist, each bringing unique nuances to the aromatic and taste profile of the wine. Some of the most noteworthy yeasts include the Saccharomyces cerevisiae species, known for its key role in alcohol fermentation. These yeasts convert sugars into alcohol, transforming the must into a fermented liquid with winemaking potential.
As well as Saccharomyces cerevisiae, there are other strains of yeast that can contribute to the complexity of the wine. Some indigenous strains, naturally present in certain winemaking regions, also play a vital role and influence the distinctive character of local wines. As they are endemic to some producing areas, they play a crucial role in the unique expression of local wines.
This melting pot of yeasts within the wine creates a diverse palette of flavors and aromas and transforms them into essential allies in the creation of unique wines. It is for this reason that the interaction between these yeasts and the specific environment of each region, and each denomination of origin, contributes to the diversity and complexity of flavor and aromatic profiles that characterize wines around the world.
As such, for example, the Torulaspora delbrueckii yeast is found in grapes of the winemaking region D.O. Rioja. This way, as it is indigenous, it can affect fermentation and contribute to the aromatic complexity of red wines and white wines from the area. The result is a wine that presents a singularity and distinctive character that must be appreciated. Good examples are Viña Zaco by Bodegas Bilbaínas, an Author wine with a complex aromatic profile thanks to the action of its yeasts, or Lumen Brut Reserva, an intense and fresh sparkling wine.
