The Silent Artisans of Winemaking: Understanding the Role of Yeasts

Dec 31, 2023Daniele Borgogno
Winery fermentation

The art of winemaking is profoundly influenced by the yeasts involved in the fermentation process. These tiny organisms not only convert grape sugars into alcohol but also significantly shape the aroma, flavor, and character of the wine. This article explores various yeast strains used in winemaking, detailing their unique properties and contributions to the wine-making process.

Yeasts in fermentation

The Impact of Yeasts on Wine

Yeasts do more than just ferment sugars; they are flavor alchemists. Different yeast strains can influence a wine’s character in several ways:

-Flavor and Aroma: Yeasts contribute to the development of specific flavor compounds, such as esters and phenols, which give wines their distinctive fruit, floral, or spicy notes.

-Texture and Mouthfeel: The by-products of yeast fermentation, like glycerol, affect the mouthfeel of wine, contributing to its body and smoothness.

-Wine’s Complexity: The choice of yeast can add layers of complexity, enhancing the depth and richness of the wine’s profile.

Autoctone Yeasts vs Selected Yeasts

Regarding safety, selected yeasts are rigorously tested. They minimize the risk of unwanted microbial activities, thus ensuring the wine’s stability and safety for consumption. In terms of naturalness, while they are cultivated in laboratories, their origin and function remain inherently natural. Autoctone yeasts, on the other hand, are wild, indigenous yeasts naturally present in the vineyard or winery. They are integral to terroir-driven winemaking, contributing unique flavors and characteristics that reflect a wine’s origin. The reality it is that the majority of these yeasts are coming from the winery itself not so much from the grape skin.


Wild Yeast: The Unpredictable Artisan

The use of autoctone yeasts can sometimes be a gamble in terms of safety and consistency. The natural diversity of these yeasts can lead to unpredictable fermentations, potentially resulting in spoilage or inconsistent quality. Both selected and autoctone yeasts have their roots in nature, but they differ in their approach to winemaking. Selected yeasts offer a safety net, ensuring a consistent, controlled fermentation process. This makes them a preferred choice for winemakers who prioritize consistency and specific flavor profiles. In contrast, autoctone yeasts embody the essence of winemaking, but with an element of unpredictability. They can create wines with distinctive, complex profiles, but the risk of fermentation-related issues is higher. In this case there could be a difference in between one vintage to an other, as the yeast it would be most likely an other one.

Selected Yeasts in Winemaking: The Microscopic Masters of Flavor and Fermentation

Selected yeasts play a pivotal role in modern winemaking, providing precision and consistency. Sourced from natural environments and cultivated under controlled conditions, they are designed to optimize the fermentation process. Unlike wild and autoctone yeasts, selected yeasts offer predictable outcomes, ensuring uniform wine quality. Their natural origins are as authentic as their wild counterparts, but with added efficiency through scientific selection and rigorous testing. Specialized yeasts, like Crio-yeasts, demonstrate the innovation possible with selected strains. These yeasts enable fermentation at lower temperatures (10°C/13°C), preserving delicate flavors and aromas. Additionally, some strains are tailored for high-alcohol environments or specific fermentation techniques, such as barrique fermentation, showcasing the versatility and necessity of selected yeasts in contemporary winemaking practices.

Certainly, yeasts are true virtuosos in the world of winemaking, contributing in an unparalleled manner to the creation of extraordinary wines. The meticulous selection of yeast strains and a deep understanding of their characteristics play a crucial role for winemakers who aspire to craft oenological masterpieces destined to delight palates around the globe. To assert that the quality of a wine depends solely on the use of indigenous yeasts or vice versa would be an inaccurate statement; it is, instead, a decision made by the winemaker based on the context and their personal convictions.

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