The journey of winemaking begins in the vineyard.  Behind the vibrant green vine leaves and juicy firm grape berries, hides an unseen ecosystem – a rich and dynamic microbial ecosystem. These microorganisms are an integral part of viticulture and oenology, albeit often unseen. They are sources of biodiversity and play important roles in various functions and balances, including nutrient cycling and maintaining the health of grapevines.¹  In winemaking, a diverse microbial ecosystem enhances fermentation efficiency and stability.² Apart from that, these site-specific microorganisms contribute to the terroir concept in winemaking – where the environment such as soil, topography, climate, and landscape characteristics influence the complexity of wine aromas and flavour profiles.³ They act as silent sculptors, crafting the character in each bottle of wine in a subtle yet distinctive way. These tiny microorganisms work silently, interacting from the vineyard to the winery, to produce a unique wine.

What shapes the microbial diversity in vineyards?

Microbiomes of vineyards – those on soil and directly associated with grapevines- are shaped by many factors including climate, topography, and viticultural practices.³ Climate, strongly influenced by topography, is a key factor shaping microbial diversity in vineyards.⁴ Studies have shown that vineyards that practice organic and biodynamic management have higher microbial diversity present, including during spontaneous fermentation where the must was found to have higher yeast species richness and diversity.⁴

From lab to vineyard: how biocontrol agents are transforming sustainable winemaking

Synthetic chemicals can be used to suppress harmful pathogens in the vineyard. However, upon application, some beneficial microorganisms are also harmed due to the toxicity of chemical compounds found in synthetic pesticides⁵. Therefore, research into biocontrol agents – a natural alternative – is on the rise to limit or replace synthetic chemicals to combat diseases in the vineyard. Biocontrol agents (BCAs), which include beneficial fungi, bacteria, and yeasts, are playing an increasingly important role in transforming viticulture. By offering natural protection against diseases such as Botrytis cinerea (grey mold), Plasmopara viticola (downy mildew), and Erysiphe necator (powdery mildew), these microbial allies are steering winemaking toward a more sustainable future. ⁶ Their use aims not only to reduce the dependence on synthetic chemicals but also to protect and enhance the natural microbial diversity vital for healthy vine ecosystems.

The power of microorganisms

Specific microorganisms have shown remarkable effectiveness in vineyard protection. Species like Aureobasidium pullulans, Bacillus spp., and Trichoderma spp. suppress pathogenic fungi by competing for nutrients and space, producing antimicrobial compounds, and stimulating the vine’s natural defenses. ^6,7 For instance, A. pullulans, has demonstrated efficacy against B. cinerea by occupying ecological niches that would otherwise be exploited by the pathogen. Similarly, Bacillus subtilis and Bacillus amyloliquefaciens produce a range of bioactive molecules that inhibit pathogen development and enhance plant immunity. Fungal agents like Trichoderma atroviride are particularly valuable for controlling grapevine trunk diseases, contributing to long-term vineyard health and resilience.

The biocontrol sector is experiencing rapid growth. The global market for biological control products exceeded USD 6.6 billion in 2022 and is projected to reach USD 13.7 billion by 2027, reflecting increasing demand for sustainable alternatives, particularly in the European viticulture sector. ⁸

A symbiotic relationship: biocontrol and biodiversity

By choosing beneficial microorganisms instead of chemical pesticides, winegrowers are not just safeguarding their vines, they’re potentially nurturing and boosting the microbial communities in their vineyards. This shift toward biocontrol plays a critical role in preserving biodiversity, promoting healthier soils, and enhancing vineyard resilience against future disease outbreaks and climate challenges. ^1,6,9

A greener path for winemaking

The future of winemaking is turning greener, with biocontrol agents as part of this transformation. By working with nature instead of against it, winegrowers protect their vines, preserve terroir, and maintain the natural balance of their vineyards. This approach helps safeguard the richness of the soils, the resilience of the plants, and the unique character of the grapes. Each harvest reflects the quiet work of the invisible life that supports healthy vines and contributes to the authentic expression of the land. ^{3,4, 9}