Insight Into the Microbial Activity and Chemical Composition Changes During Wine Aging and the Establishment of a Minimally Interventionist System for Natural Wine

In recent years, natural wines have become a hot research topic due to their unique flavor complexity and diversity. However, the dynamic changes in constituents during the aging process of natural wines are highly intricate, and the mechanism of microorganisms has not yet been fully and deeply analyzed. This situation has seriously restricted the quality control of natural wines and the optimization of the winemaking process. This paper presents a critical review synthesizing existing knowledge on the aging of natural wines. From the physicochemical point of view, redox and polymerization reactions drive the transformation of phenolic compounds, which in turn trigger the evolution of the wine's color and the softening of the palate. From the microbiological point of view, the activity of microorganisms such as acetic acid bacteria and lactic acid bacteria tends to elevate the content of volatile acids in wines, which produces undesirable flavors, whereas polysaccharides released by yeasts in the process of autolysis help to enhance the complexity of the wine body. Moreover, aging conditions can regulate oxidation rates and microbial communities, thereby achieving a balance between wine stability and sensory characteristics; lees aging can delay oxidative deterioration in wine; it highlights the unique challenges and strategies faced by natural wines due to minimal intervention. This paper synthesizes and critically evaluates the current research on wine aging process, aiming to improve the understanding of the compositional changes during wine aging, and to provide a theoretical basis for microecological regulation and process optimization during natural wine aging.