How does the microbial composition of grapes and fermenting must influence wine mouthfeel?
Wine mouthfeel is a crucial aspect of the overall wine-drinking experience. It refers to the sensory perceptions in the mouth when wine is tasted, including aspects like texture, body, astringency, and viscosity. The microbial composition of grapes and fermenting must plays a significant role in shaping these characteristics.
Microbial Composition of Grapes
The microbial composition of grapes, particularly the presence of yeast and bacteria, can have a direct impact on the eventual mouthfeel of the wine produced. Here’s how:
- Yeast strains: Different yeast strains present on the grape skins can contribute unique flavors and textures to the wine. For example, certain yeast strains may produce compounds that enhance the mouthfeel by adding creaminess or roundness to the wine.
- Bacterial presence: Lactic acid bacteria, commonly found on grape skins, can influence the mouthfeel of wine through processes like malolactic fermentation. This bacterial fermentation can reduce acidity levels and soften the wine’s overall texture.
Fermenting Must
During the fermentation process, the microbial composition of the must (crushed grape juice) further shapes the wine’s mouthfeel. Here’s how this happens:
- Yeast activity: The yeast present in the must consumes sugars and produces alcohol, carbon dioxide, and various compounds that influence mouthfeel. For example, yeast may produce glycerol, a compound that contributes to a wine’s body and texture.
- Malolactic fermentation: If malolactic fermentation occurs in the must, bacteria can convert harsh malic acid into softer lactic acid, impacting the perceived acidity and smoothness of the wine.
Influence on Wine Mouthfeel
The microbial composition of grapes and fermenting must can influence wine mouthfeel in several ways:
- Texture: Certain yeast strains can produce polysaccharides that contribute to a wine’s mouthfeel, creating a smoother or creamier texture.
- Body: The presence of specific yeast strains and fermentation byproducts, like glycerol, can enhance the body of the wine, making it feel fuller and more substantial on the palate.
- Astringency: Tannins, compounds present in grape skins and seeds, can contribute to a wine’s astringency. The microbial composition can impact how these tannins are extracted and perceived in the final wine.
- Acidity: Bacterial fermentation processes like malolactic fermentation can reduce the perceived acidity of the wine, leading to a softer mouthfeel.
Factors Affecting Microbial Composition
Several factors can influence the microbial composition of grapes and fermenting must, ultimately affecting wine mouthfeel:
- Grape variety: Different grape varieties host unique microbial populations, which can impact the fermentation process and the resulting mouthfeel of the wine.
- Growing conditions: Environmental factors like climate, soil composition, and vineyard practices can shape the microbial profile of grapes, influencing the fermentation and mouthfeel of the wine.
- Winemaking techniques: Choices made during the winemaking process, such as temperature control, use of sulfites, and fermentation vessels, can impact the growth of specific microbes and their effects on mouthfeel.