Fermentation and Biotechnology in Wine Making

The winemaking sector is currently experiencing a period of deep transformation, driven by the convergence of traditional oenological knowledge with advances in biotechnology, microbial ecology, analytical chemistry, and sustainable production systems.

This Special Issue brings together five original research articles that collectively highlight the diversity and relevance of current scientific advances in fermentation and wine biotechnology.

The featured studies explore different dimensions of modern oenology, including microbial management, fermentation performance, wine composition, technological innovation, and quality optimization. These dimensions, when applied correctly, may present an opportunity for the revival of ancestral fermentations using fruits other than grapes (Contribution 1) or ancient grape varieties (Contribution 2). Together, these contributions provide valuable insights into both fundamental and applied aspects of wine science.

Wine fermentation is no longer understood merely as a biochemical conversion of sugars into ethanol. Instead, it represents a highly dynamic and multifactorial biological process in which yeasts, bacteria, enzymatic activities, environmental conditions, and technological interventions collectively shape the sensory, chemical, and functional properties of wine. All of these factors can only positively influence wine quality if the raw material is not neglected. As popularly stated, “there are no good wines without good grapes”. In particular, grape quality as influenced by foliar nutrition was shown to influence juice nutritional composition (Contribution 3).

Nevertheless, in a time where fermentations without intervention have become popular, it must be emphasized that without appropriate technology, all wine becomes vinegar. The revival of ancestral winemaking techniques must be performed while bearing in mind that uncontrolled fermentations increase the risk of wine spoilage (Contribution 2). Among the agents of spoilage, lactic acid bacteria continue to represent a major risk. Their tendency to decrease sulphite levels makes the search for effective alternatives of utmost importance. In their work, Kostelnikova et al. (Contribution 4) showed the effect of an array of preservatives like chitosan, fumaric acid, and a tannin-based oenological preparation on medium-chain fatty acids and selected hydroxycinnamic acids. The species were not limited to Oenococcus oeni but included Lactobacillus brevis and Lactobacillus plantarum.

Other recurring themes emerge from the articles included in this issue. Recent developments in microbial biotechnology have demonstrated that non-Saccharomyces yeasts and lactic acid bacteria can significantly contribute to aroma complexity, mouthfeel, and regional expression. Indeed, one important topic concerns the role of lactic acid bacterial strains of Oenococcus oeni in shaping fermentation dynamics and wine typicity (Contribution 5). These authors were faced with the challenge of ensuring malic acid bioconversion in wines produced with Japanese indigenous Koshu grapes. The low pH of these wines (pH 3.0) is known to be highly inhibitory. Nonetheless, several Oenococcus oeni strains isolated from these wines were shown to efficiently perform this challenging task. Understanding and controlling these microbial consortia represent a key frontier for precision oenology.

The articles also emphasize the importance of advanced analytical methodologies in characterizing wine composition and fermentation behaviour. Modern omics technologies, metabolomics, and high-resolution analytical tools are increasingly enabling researchers to better understand microbial metabolism and its influence on volatile and non-volatile compounds.

Beyond scientific innovation, sustainability emerges as a transversal concern throughout contemporary wine research. The reduction in chemical inputs, valorization of by-products, improvement of energy efficiency, and development of environmentally friendly fermentation practices are becoming central objectives for the wine industry worldwide. The advances presented in the studies of this Special Issue may be used by other research teams directly focused on the broader transition toward more sustainable and resilient winemaking systems.

As Guest Editors, we would like to express our sincere gratitude to all the authors who contributed their valuable work to this Special Issue. We also thank the reviewers for their rigorous evaluations and constructive comments, which greatly contributed to maintaining the high scientific quality of the published manuscripts. Finally, we acknowledge the editorial team for their continuous support and efficient management throughout the editorial process.

We hope that the articles featured in this Special Issue will stimulate further research and interdisciplinary collaboration in the fields of wine fermentation and biotechnology. The integration of microbiology, biotechnology, chemistry, engineering, and sensory science will continue to play a decisive role in addressing future challenges and opportunities in the global wine sector.