How can yeast fermentation preserve a fruit product?

Yeast fermentation preserves fruit products primarily through the production of ethyl alcohol. During this process, yeasts break down the sugars present in the fruit into alcohol and carbon dioxide.12

When the concentration of ethyl alcohol increases sufficiently, it acts as a chemical preservative that helps stabilize the fruit product. This method is a form of chemical preservation where the action of microorganisms creates an environment that inhibits spoilage. In some food processing contexts, fermentation is combined with other techniques, such as salting, to selectively control microorganisms and further stabilize the treated tissues.13

It is important to note that while fermentation can be a preservation tool, yeasts are also considered agents of spoilage in other fruit contexts because they can grow in the acidic environment of fruits and break down their components. Therefore, successful preservation through fermentation requires careful control of conditions—such as temperature, acidity, and the exclusion of oxygen—to ensure that desirable yeast strains dominate and effectively preserve the product.24