What role does carbon dioxide play in fermentation?

Carbon dioxide plays a crucial role in the fermentation process, particularly in relation to sparkling wines. During fermentation, yeast converts sugars into alcohol and produces carbon dioxide as a byproduct. In the production of sparkling wines, the presence of carbon dioxide is essential as it contributes to the bubbles or effervescence that gives these wines their distinct characteristics.

The method typically known for creating sparkling wine, méthode champenoise for instance, involves a second fermentation in the bottle, which produces more carbon dioxide. This gas dissolves into the wine under pressure, and when the bottle is opened, the pressure is released, allowing the carbon dioxide to form bubbles. Therefore, the correct choice highlights the significant influence that carbon dioxide has on the sparkling characteristics of wine, making it key to the desired mouthfeel and overall experience of sparkling wine.