Microorganisms play a crucial role in the production of dessert wines and late harvest wines. These tiny organisms, such as yeast and bacteria, contribute to the fermentation process that transforms grape juice into delicious, sweet wines that are beloved by many wine enthusiasts.
Fermentation Process
One of the key ways that microorganisms contribute to the production of dessert wines and late harvest wines is through the fermentation process. During fermentation, yeast consumes the sugars present in the grape juice and produces alcohol as a byproduct. This process is essential for creating the rich, complex flavors that are characteristic of dessert wines.
Botrytis Cinerea
In the case of late harvest wines, a specific type of fungus called Botrytis cinerea plays a significant role in the production process. This fungus, also known as “noble rot,” infects ripe grapes and causes them to shrivel up, concentrating their sugars and flavors. When these grapes are then harvested and fermented, they produce intensely sweet and flavorful wines.
Acids and Aromas
Microorganisms also play a role in shaping the acidity and aroma profiles of dessert wines and late harvest wines. During fermentation, certain strains of yeast can produce acids that contribute to the overall balance of the wine. Additionally, the metabolic activities of these microorganisms can release volatile compounds that give the wine its characteristic aromas.
Fortification
In some cases, microorganisms are also involved in the fortification process used to produce fortified dessert wines like Port and Sherry. Fortification involves the addition of a distilled spirit, such as brandy, to the wine to stop fermentation and preserve the wine’s sweetness. Certain strains of yeast are used to ferment the base wine before fortification, contributing to the overall flavor profile of the final product.
Role of Bacteria
While yeast is the primary microorganism involved in the fermentation of dessert wines and late harvest wines, certain types of bacteria can also play a role in the production process. For example, lactic acid bacteria can participate in malolactic fermentation, which softens the acidity of the wine and adds complexity to its flavor profile.
Quality Control
Microorganisms can also serve as indicators of the quality of the wine during production. Winemakers closely monitor the populations of yeast and bacteria present in the fermentation tanks to ensure that the process is proceeding as expected. By controlling the growth and activity of these microorganisms, winemakers can influence the final taste, aroma, and texture of the wine.
Impact of Microorganisms on Wine Styles
The specific strains of yeast and bacteria present during fermentation can have a significant impact on the style and characteristics of the final wine. Different microorganisms produce different compounds during fermentation, leading to variations in sweetness, acidity, aroma, and flavor profile. This diversity allows winemakers to create a wide range of dessert wines and late harvest wines with unique and complex characteristics.