Wine Dealcoholization: State of the Art and Effects on Chemical Composition

Introduction

This video covers wine dealcoholization techniques, a growing topic of interest in oenology, especially as consumer demand for low-alcohol products rises. The presentation outlines the primary technologies available and their impact on wine quality, with a focus on climate change and shifting consumer preferences.

Historical Context and the Evolution of Wine Quality

The relationship between alcohol content and perceived wine quality has changed over time. Historically, alcohol was a primary factor in determining both price and quality. However, today, sensory quality, stability, and origin are more significant indicators of wine’s value to consumers.

Increasing Alcohol Content in the Context of Climate Change

One of the central topics is the global rise in the average alcohol content of wines, driven largely by global warming. Higher temperatures accelerate grape maturation, increasing sugar levels, which leads to higher alcohol content in the finished wine. However, this can create quality imbalances, as phenolic and aromatic ripeness do not always align with technological maturity.

Consumer Preferences and the Growing Demand for Low-Alcohol Wines

In recent decades, consumer interest in low-alcohol wines has grown, driven primarily by health concerns, the desire for alcohol moderation, and healthier lifestyle choices. Factors influencing this trend include:

• Increased attention to calorie intake.
• Concerns about health and stricter DUI laws.
• Religious factors and social conditioning.

Marketing research identifies the primary consumers of these products as women, millennials, and individuals with lower-to-moderate incomes.

Techniques to Reduce Alcohol Content in Wine

There are several techniques to control and reduce the alcohol content in wine, divided into the following categories:

1. Viticultural Strategies

• Selection of grape variety, rootstock, and cultivation site.
• Practices to limit sugar accumulation in the grapes while ensuring proper phenolic and aromatic maturation.

2. Pre-Fermentation Strategies

• Blending musts with different sugar levels.
• Adding water to the must (a practice allowed in countries like Australia).
• Using enzymes to reduce glucose (currently not allowed in Europe).

3. Fermentation Techniques

• Altering the sugar-to-alcohol conversion yield.
• Utilizing selected yeast strains to reduce ethanol production.

4. Post-Fermentation Techniques

• Dealcoholization through distillation or membrane technologies.
• Distillation: separating ethanol from wine using spinning cone columns.
• Membrane technologies: using reverse osmosis or nanofiltration to remove alcohol.

Impact of Dealcoholization on Wine Quality

Ethanol is not just a sensory-active compound; it also influences body, viscosity, bitterness, sweetness, and overall balance. Dealcoholization results in a loss of volatile aromas, especially esters responsible for fruity notes, which can significantly alter the wine’s sensory profile.

Conclusions

While dealcoholization techniques have improved over the years, challenges remain. Dealcoholized wines undergo significant changes in taste and aroma, depending on the amount of alcohol removed. Selecting the right technique and applying it strategically is crucial to minimizing the negative impact on wine quality. For wines with moderate alcohol reductions, integrating viticultural, pre-fermentation, and fermentation strategies can help achieve the desired result with minimal need for post-fermentation dealcoholization.