Penn State study finds small-batch wine fermentation matches results of larger trials

A recent study from Penn State University has found that microvinification, or fermenting wine in batches as small as 50 milliliters, can reliably replicate the results of much larger fermentation trials. This research, published in the American Journal of Enology and Viticulture, could change how winemakers and researchers approach product development and quality testing.

Traditionally, wineries and research institutions use pilot-scale fermentations of about five gallons to evaluate grape quality, yeast performance, and winemaking techniques. These larger trials require significant time, labor, and resources. The Penn State team, led by associate research professor Misha Kwasniewski and doctoral student Ezekiel Warren, set out to determine if much smaller fermentations could provide the same insights at a fraction of the cost.

The researchers conducted side-by-side fermentations using both 50-milliliter microvinifications and standard five-gallon batches. They used two grape varieties, Chambourcin and Noiret, harvested from the same vineyard blocks. All grapes were destemmed, crushed by hand, and inoculated with yeast under controlled conditions. The team monitored key variables such as oxygen exposure, fermentation temperature, cap management (the mixing of grape solids), and maceration time (the duration grape skins remain in contact with juice).

Chemical analyses focused on phenolic compounds, which influence color and mouthfeel, as well as aromatic compounds that affect aroma and flavor. The results showed that the tiny fermentations closely matched the chemical profiles of their larger counterparts. Concerns that microvinifications would be more susceptible to oxygen-related problems or inconsistent outcomes proved unfounded.

Kwasniewski explained that the key to reliable results is proper replication—conducting enough repeated tests to account for natural variation. He emphasized that microvinifications can be a powerful tool for improving research accuracy and predicting wine outcomes based on grape chemistry. This approach also supports commercial decision-making by allowing winemakers to test interventions such as harvest timing or yeast selection without committing large quantities of fruit.

The study challenges a common industry belief that only large-scale trials yield meaningful data for wine production. Kwasniewski noted that this mindset can slow innovation and increase costs for both researchers and producers. By demonstrating that microvinifications are not more prone to technical issues like oxygen exposure, the research suggests these small-scale tests are a practical alternative for experimentation.

Alex Fredrickson, a fermentation consultant at Terroir Consulting Group in Oregon and former doctoral student advised by Kwasniewski, also contributed to the project. The work was funded by the US Department of Agriculture’s National Institute of Food and Agriculture.

The findings may encourage more wineries to adopt microvinification for research and development purposes. This could accelerate innovation in winemaking techniques while reducing waste and expense. As the industry faces ongoing challenges related to climate change, supply chain disruptions, and shifting consumer preferences, efficient tools like microvinification could play an important role in helping producers adapt quickly.

The Penn State study provides new evidence that small-scale fermentations can deliver big benefits for wine research and production. With further adoption, microvinification may become a standard practice in wineries looking to refine their products with greater speed and precision.