Malolactic fermentation (MLF) is a crucial process in winemaking that plays a significant role in the efficiency and quality of the final product. It is important to understand the science behind this process and its impact on the characteristics of different wines.
MLF is not actually a fermentation, but rather a decarboxylation process. It occurs when specific bacteria, known as Lactic Acid Bacteria (LAB), convert malic acid into lactic acid, releasing carbon dioxide in the process. This conversion results in a reduction of acidity in the wine, which can have a significant impact on its taste and mouthfeel.
While MLF is commonly associated with red wines, it is also utilized in the production of certain white wines such as Chardonnay and Viognier. One way to identify whether MLF has occurred in a wine is by noting a creamy, oily texture on the mid-palate. This texture can indicate the presence of MLF or lees aging, another process that can contribute to a similar mouthfeel.
The primary role of MLF in winemaking is threefold. Firstly, it helps to reduce the overall acidity of the wine. Malic acid, which is naturally present in grapes, can contribute to a sharp or tart taste. By converting malic acid into lactic acid, MLF helps to create a smoother and more balanced flavor profile.
Secondly, MLF can contribute to the stability of the wine. Malic acid can serve as a potential carbon source for spoilage microorganisms, which can lead to off-flavors and spoilage of the wine. By removing malic acid through MLF, the wine becomes less susceptible to microbial spoilage, ensuring its quality and safety.
Lastly, MLF can result in significant aroma and flavor changes in the wine. The conversion of malic acid to lactic acid can contribute to the development of complex, buttery, and creamy flavors. These changes can enhance the overall sensory experience of the wine, making it more enjoyable for consumers.
The process of MLF is primarily driven by LAB, particularly species such as Oenococcus oeni and Lactobacillus. These bacteria can naturally occur on grape skins or can be added to the wine intentionally as a starter culture. The conditions for MLF, such as temperature and pH, must be carefully controlled to ensure the successful completion of the process.
Malolactic fermentation is a critical process in winemaking that has a significant impact on the characteristics of different wines. It helps to reduce acidity, stabilize the wine, and contribute to aroma and flavor changes. By understanding the science behind MLF, winemakers can better control and enhance the quality of their final products.
What Is The Purpose Of Malolactic Fermentation?
The purpose of malolactic fermentation (MLF) in winemaking is multifaceted and serves several important functions:
1. Reduction of acidity: MLF helps to reduce the overall acidity of the wine by converting the harsher malic acid into softer lactic acid. This process can result in a smoother and more balanced wine, as excessive acidity can be perceived as tart or sharp on the palate.
2. Stabilization: MLF also aids in stabilizing the wine by removing a potential carbon source. Malic acid can act as a nutrient for spoilage microorganisms, such as certain types of bacteria or yeast, which can lead to off-flavors or spoilage. By converting malic acid into lactic acid, MLF removes this potential food source and reduces the risk of microbial spoilage.
3. Aroma and flavor changes: In addition to its acid-reducing and stabilizing effects, MLF can also contribute to the development of desirable aroma and flavor characteristics in wine. The conversion of malic acid to lactic acid can produce compounds that contribute to the complexity and richness of the wine, such as diacetyl, which imparts buttery or creamy flavors. MLF can also result in the formation of secondary metabolites, such as esters and aldehydes, which can enhance the fruity or floral aromas of the wine.
The purpose of malolactic fermentation in winemaking is to reduce acidity, stabilize the wine by removing a potential carbon source, and contribute to the development of desirable aroma and flavor characteristics.
Conclusion
Malolactic fermentation is a crucial process in wine production that occurs in nearly all red wines and some white wines such as Chardonnay and Viognier. It is not actually a fermentation, but rather a decarboxylation process carried out by Lactic Acid Bacteria (LAB). The LAB cells convert malate into lactate, releasing carbon dioxide in the process. This transformation reduces the acidity of the wine and contributes to its flavor and aroma profile.
Malolactic fermentation also plays a role in stabilizing the wine by removing a potential carbon source and improving microbial stability. The presence of MLF can be detected by the creamy, oily mid-palate texture it imparts to the wine. This texture can also be attributed to lees aging, which is often associated with MLF.
Malolactic fermentation enhances the quality and safety of wine by reducing acidity, producing flavor and aroma changes, and improving mouthfeel. It is an important process that winemakers carefully control to achieve the desired characteristics in their wines.
