What is the fermentation process in wine production?

During fermentation, yeast transforms sugar into alcohol and carbon dioxide. This process occurs in wine production when yeast is added to grape juice, which is then sealed and left to ferment for several weeks to several months. The yeast consumes the sugar in the grape juice and produces alcohol and carbon dioxide as by-products. The alcohol becomes the wine, and the carbon dioxide is either released into the air or dissolved in the wine, depending on the type of wine being made.