Indigenous vs. commercial yeasts
Wine has been an important part of human culture for thousands of years, and today it is enjoyed by people all over the world. While many people are familiar with the basic process of winemaking – grapes are harvested, crushed, and fermented with yeast – there is actually a great deal of variation in how different wines are produced. One of the key decisions that winemakers must make is whether to use indigenous yeasts or commercial yeasts during the fermentation process. In this article, we will explore the differences between these two approaches and examine some of the pros and cons of each.
What are Yeasts?
First, let's take a step back and look at what yeasts are and how they are involved in winemaking. Yeasts are tiny microorganisms that are naturally present on grape skins, and they play a crucial role in turning grape juice into wine. During the fermentation process, yeasts consume the sugar in the grape juice and produce alcohol and carbon dioxide as byproducts. This is what gives wine its characteristic flavor, aroma, and texture.
Indigenous yeasts, also known as wild yeasts, are naturally occurring strains of yeast that are present on grape skins and in the winery environment. These yeasts are unique to each vineyard and winery, and they have the potential to create wines with distinct regional characteristics. Indigenous yeasts are often favored by winemakers who prioritize terroir, or the unique environmental factors that influence a wine's flavor and aroma.
One of the benefits of using indigenous yeasts is that they are well adapted to the local environment, which can lead to a more robust fermentation process. These yeasts have evolved to thrive in the particular conditions of a given vineyard, and they may be better equipped to handle the fluctuations in temperature and humidity that can occur during the winemaking process.
Another advantage of using indigenous yeasts is that they can contribute to the complexity and nuance of a wine's flavor profile. Since these yeasts are unique to a particular vineyard, they can produce wines with distinctive flavors and aromas that are reflective of the local terroir. Some winemakers believe that using indigenous yeasts can result in more expressive and authentic wines.
However, using indigenous yeasts does come with some risks. Because these yeasts are not specifically selected for their winemaking properties, they may not be as reliable or predictable as commercial yeasts. Indigenous yeasts may have a slower fermentation rate, which can increase the risk of spoilage or off-flavors. In addition, since the yeasts are not isolated and cultured in a lab, they may be contaminated with other microorganisms that can negatively impact the wine.
Commercial yeasts are strains of yeast that have been specifically developed and cultured for winemaking. These yeasts are often chosen for their ability to produce consistent, predictable results, and they are widely used in the wine industry. Commercial yeasts come in a variety of strains, each with its own unique flavor profile and fermentation properties.
One of the primary benefits of using commercial yeasts is that they offer a high degree of control over the winemaking process. Since these yeasts are carefully selected and cultured in a lab, winemakers can choose a specific strain that is well-suited to their particular grape variety, fermentation temperature, and other factors. This can lead to a more reliable fermentation process with fewer risks of spoilage or off-flavors.
Another advantage of using commercial yeasts is that they can help winemakers achieve a consistent flavor profile from vintage to vintage. Since the yeasts are chosen for their specific flavor and aroma properties, winemakers can use the same strain year after year to create wines with similar characteristics.
However, some winemakers argue that using commercial yeasts can result in wines that lack nuance and complexity. Because these yeasts are designed to produce consistent results, they may not be as expressive or reflective of the local terroir as wines made with indigenous yeasts. Some wine enthusiasts argue that commercial yeasts can result in wines that taste generic or lack a sense of place.
Another potential disadvantage of using commercial yeasts is that they can be more expensive than using indigenous yeasts. Since these yeasts are typically sold by specialized suppliers, winemakers must purchase them at a premium price. In addition, some winemakers may prefer not to use commercial yeasts on principle, as they feel that it goes against the natural, traditional spirit of winemaking.
Overall, the choice between using indigenous yeasts and commercial yeasts is a complex one that depends on a variety of factors, including the winemaker's goals, the grape variety being used, and the local terroir. While commercial yeasts offer a high degree of control and consistency, they may produce wines that lack nuance and complexity. On the other hand, indigenous yeasts can result in more expressive, terroir-driven wines, but they may be less reliable and more difficult to work with.
Ultimately, the decision of whether to use indigenous or commercial yeasts is up to each individual winemaker. By weighing the pros and cons of each approach, winemakers can choose the method that best suits their needs and goals, and create wines that are unique, expressive, and reflective of their local terroir.