(RGJ) - The production of wine would not be possible without yeasts, the microscopic organisms that actually convert sugar into alcohol and carbon dioxide. In fact, much of the aromas and flavors of wine as we experience them result from yeast activity rather than something inherent in the grape. You might hear a winemaker say, “I used only natural yeasts during fermentation.” What does this mean? And do natural yeasts mean the wine is better? The term “natural” yeast is misleading because all yeasts used in fermenting wine, with the exception of two that are genetically modified organisms and not commonly used, are natural. The correct term would be “indigenous” yeast, meaning the yeast used during fermentation was present in the environment and not added by the winemaker.