This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A new study has demonstrated that regional microbial imprints can remain detectable under commercial winemaking conditions. The research, appearing in Applied and Environmental Microbiology, shows that inoculated fermentations do not "override" native microbial diversity and that vineyard management and environmental conditions affect wine quality.
The study helps explain why wines from different regions taste distinct even when made with similar techniques and supports regional flavors and branding. "Regional identity in wine is biologically encoded, and microbes from different vineyards behave differently and influence wine chemistry and aroma. Because microbial communities are shaped by geography, climate and viticultural practices, these factors indirectly influence fermentation outcomes and the regional typicity of wines," said corresponding study author Kalliopi Rantsiou, Ph.D., professor of food microbiology and coordinator of the master's degree in viticulture and enology at the University of Turin's Department of Agricultural, Forest and Food Sciences in Italy.
"Furthermore, commercial inoculation does not entirely erase microbial signatures associated with the origin of the grapes." The researchers conducted their study because recent research has shown that grape-associated microbial communities are not randomly distributed but exhibit clear biogeographical structuring—meaning different regions harbor distinct microbial assemblages. These microbial differences can influence fermentation dynamics, organic acid metabolism and volatile compound formation. This concept, often referred to as microbial terroir, has become a major frontier in wine science.
However, despite this growing body of work, a gap remained: almost all microbial terroir studies have focused on spontaneous fermentations or pre-fermentation grape microbiota. Very few have tested whether these regional microbial signatures persist when winemakers use commercial yeast inoculation, a common practice in modern wineries. The researchers set out to determine whether microbial terroir persists under inoculated fermentation and whether it still influences fermentation dynamics, chemical composition and wine aroma.
The aim was to test whether microbial terroir is robust enough to withstand inoculation and remain a meaningful contributor to regional wine identity—a question of high relevance for both science and industry. Nebbiolo grapes provided an ideal model for the study because they are grown across distinct regions with strong environmental contrasts and are known to have complex fermentative microbiota. The researchers collected Nebbiolo grapes from 38 vineyards across three regions in northern Italy.
All grapes were fermented under identical small-scale winery conditions using the same commercial yeast strain, temperature, equipment and nutrient additions. This strict standardization ensured that any differences observed in microbial behavior or wine chemistry were due to the grapes and their native microbes, not the winemaking process. Throughout fermentation, the researchers repeatedly sampled the must, the freshly crushed juice of grapes, and wine to assess the microbes present, changes in microbial communities over time, fermentation chemistry and aroma compound development.
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