Missed the most recent monthly webinars? Below are summaries of the last two presentations. Join our next webinar in October.

May Webinar: Stilbenes Can Impair Malolactic Fermentation with Strains of Oenococcus oeni and Lactobacillus plantarum

Presented by: Fabian Weber, University of Kassel and Pascal Wegmann-Herr, DLR Rheinpfalz, Germany

Moderated by: Megan Hall

Wine is made up of various microorganisms that interact in complex ways. These include microorganisms from the grapes themselves and those influenced by viticultural practices. This presentation focused on a specific fermentation process known as malolactic fermentation (MLF), which follows alcoholic fermentation.

Researchers discussed their work investigating the impact of phenolic compounds on MLF in wine production, including the potential implications of their findings and how different phenolic compounds might affect the fermentation process. They also explored the complexity of the wine production process, considering factors such as grape varieties, fungal infections, pH levels and more.

• Malolactic Fermentation (MLF): MLF is carried out by lactic acid bacteria and involves the conversion of malic acid to lactic acid. This process leads to a decrease in acidity and can impact the taste, aroma, and color of the wine. MLF is influenced by factors such as grape variety, grape health, and enological practices.
• Stilbenes and Their Impact: Researchers investigated the effects of a group of compounds called stilbenes on MLF. Stilbenes are found in grapes and have been associated with certain health benefits. However, certain grape varieties rich in stilbenes were found to experience difficulties in MLF.
• Research Setup: Researchers created a simplified model solution to study the effects of stilbenes on MLF. They added different types of stilbenes and grape shoot extract to the solution, then observed the impact on two strains of lactic acid bacteria involved in MLF.
• Strain-Dependent Effects: The results showed that the impact of stilbenes on MLF is dependent on the specific strains of lactic acid bacteria. Some strains were inhibited by certain stilbenes, while others were not affected or even enhanced in their activity. This suggests that different strains respond differently to stilbenes, making the process complex and strain-specific.

In conclusion, the study highlights that the relationship between grape phenolic compounds such as stilbenes and the behavior of lactic acid bacteria is intricate and varies with different strains. There is need for careful consideration of MLF starter cultures based on grape variety and health, as well as the potential use of certain phenolic compounds to manage grape infections and enhance wine quality.

Read the Article on AJEV: Stilbenes Can Impair Malolactic Fermentation with Strains of Oenococcus oeni and Lactobacillus plantarum

July Webinar: Effects of Viticultural Mechanization on Working Time Requirements and Production Costs

Presented by: Larissa Strub, Simone Loose, and Andreas Kurth from Hochschule Geisenheim University, Germany

Moderated by: Lindsay Jordon, Constellation Brands

In the ever-evolving landscape of viticulture, the role of mechanization has emerged as a crucial factor in shaping both working time requirements and production costs. This presentation examined the significance of this trend.

• Labor Efficiency Enhancement: Mechanization has proven to be a game-changer in improving labor efficiency. By automating tasks such as pruning, harvesting, and canopy management, vineyard operators can significantly reduce the time required to perform these activities. This not only addresses labor shortages often faced during peak seasons but also minimizes physical strain on workers.
• Impact on Production Costs: There is a profound effect of mechanization on production costs. While the initial investment for machinery and technology can be substantial, the long-term savings in labor and increased productivity can substantially outweigh these costs. Proper maintenance and strategic implementation are key to maximizing return on investment.
• Variability in Mechanization Suitability: Not all vineyards or tasks can be uniformly mechanized. Factors such as vineyard layout, terrain, grape varieties, and quality goals influence the feasibility and effectiveness of mechanized solutions. Vineyard managers must assess which tasks are  best suited for mechanization while considering site-specific conditions.
• Data-driven Decision-making: Mechanization extends beyond physical machinery. The integration of data collection and analysis, such as vine health monitoring and yield prediction, enables informed decision-making. Real-time data is critical to properly adjusting mechanization strategies and optimizing overall operations.
• Skilled Workforce Evolution: Mechanization shifts the demand for labor from manual labor-intensive tasks toward technical oversight and machinery management. This shift highlights the need for training labor forces to handle advanced machinery, driving a new wave of education and training in the viticulture sector.

Read the Article on AJEV: Effects of Viticultural Mechanization on Working Time Requirements and Production Costs