How does fermentation help preserve foods?

Fermentation preserves food by utilizing microorganisms to transform the chemical composition of the product, creating an environment that inhibits spoilage. This process often involves the conversion of carbohydrates into acid or alcohol, which helps stabilize the treated tissues.12

A common preservation technique combines salting with fermentation to selectively control the growth of microorganisms. In many products, such as fermented milk or pickles, bacteria produce lactic acid, which acts as a preservative by increasing acidity. This acidic environment is generally unfavorable for the growth of many spoilage-causing bacteria.1345

While fermentation is an effective stabilization method, these products still require protection against molds, which can metabolize the developed acid and allow other microorganisms to advance. For long-term storage, additional measures such as canning or cool storage are often necessary to maintain stability. Overall, fermentation not only preserves food but also retains its nutritional value, and in some cases, can even enhance nutrient levels through the activity of yeasts.2