INDICE
In winemaking, managing oxygen exposure is critical, particularly for white and rosé wines. Oxygen contamination can lead to undesirable oxidation, which diminishes the freshness, longevity, and overall quality of the wine. In this video extract, taken from the presentation “Good Oxygen Management Practices to Improve Wine Sensory Profile” given by Dominique Delteil, we’ll explore the best practices for protecting white and rosé wines from oxidation, especially in organic winemaking.
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Key Stages of the Process
From the moment grapes are harvested, careful oxygen management is essential. The process begins with grape harvesting, followed by crushing, destemming, pressing, and juice clarification. Each step requires attention to detail to minimize oxygen exposure. During alcoholic fermentation, especially for those aiming for a fresh and mineral white wine, using oak staves in stainless steel tanks can be beneficial. This technique enhances the wine’s complexity and longevity while maintaining a clean, mineral profile.
Role of SO2 in Oxygen Management
Sulfur dioxide (SO2) plays a critical role in protecting wine from oxygen. In the early stages, SO2 blocks oxidation chains initiated by oxidase enzymes. While SO2 doesn’t directly react with oxygen, it halts the chain reactions that oxygen stimulates. Proper SO2 management is key, and it’s vital to monitor levels throughout the winemaking process.
To protect organic wines, winemakers must find a balance between pH and SO2 levels. The recommended pH for optimal protection of white and rosé wines is crucial, particularly when working with organic SO2 levels. Regular measurements of free SO2 after each racking help ensure adequate protection during aging.
Calculating Free SO2
Calculating free SO2 accurately requires considering several factors, including pH, alcohol content, and temperature. Maintaining about 1 mg/L of molecular SO2 ensures stability and contributes to the wine’s longevity.
Bottling and Final Adjustments
Before bottling, winemakers should adjust the free SO2 to keep the total SO2 levels below 100 mg/L. In addition to SO2, ascorbic acid is often used in conjunction to provide further protection. It’s important to use pure ascorbic acid and ensure its proper management to avoid excessive oxidation. When used correctly alongside SO2, the two work synergistically to safeguard the wine.
Common Mistakes to Avoid
One common error in winemaking is measuring free SO2 without accounting for interference from ascorbic acid. Using a reliable method to measure free SO2 helps avoid these mistakes.
In more challenging winemaking situations, such as dealing with grapes affected by botrytis, specialized techniques can help prevent oxidation. For more detailed guidance on these cases, check out the winemaking chronicles on our website
Conclusion
Proper oxygen management is essential for producing high-quality white and rosé wines. By balancing SO2 and pH levels and using appropriate oxygen control techniques, winemakers can enhance the freshness, mineral qualities, and longevity of their wines. Stay tuned for more insights into advanced winemaking techniques and their practical applications.
If you want to learn more about this topic on Infowine Premium there is the entire presentation “Good Oxygen Management Practices to Improve Wine Sensory Profile” given by Dominique Delteil.
