Assessment of On-Skin Microvinification in the Evaluation of Berry-Derived Wine Flavor Components

Background and goals Wine results from the complex interplay between berry chemistry, microbial metabolism, and other abiotic factors. The unpredictability of the final product of these interac-tions often necessitates fermentations to assess fruit qual-ity, yeast metabolism, etc. Pilot-scale (20 L) fermentation-based experiments with adequate replication are time intensive and costly, although there is also a hesitancy to utilize microvinification (~50 mL). This is because of con-cerns that small fermentations are highly variable, prone to excessive oxygen exposure, or may lead to other issues, despite previous research demonstrating otherwise. To evaluate these questions, this study investigates previously uncharacterized elements of microvinification, including O₂ ingress and the effects of temperature, cap management, and extraction time on wine phenolic and aroma profiles. Methods and key findings The O₂ pickup, phenolic extraction, and volatile release of fermentation in 50-mL microvinifications were quanti-fied and compared to 20-L pilot-scale fermentations. The microvinifications produced consistent results, with no evidence of excess O₂ pickup or variability. Phenolic extraction and volatile production varied in some vinifications according to the cap integration method, temperature, and maceration time. Treatment effects similar to those of l arger-scal e fermentations in previous studi es were frequently noted. Conclusions and significance Microvinifications offer convenience in predicting postfer-mentation chemistry and yield consistent results with no oxidation problems. Wines similar in phenolic and aroma chemistry to pilot-scale fermentations can be produced on the 50-mL scale provided that representative samples with enough replications are analyzed. Thus, microvinifications can be a valuable tool in improving resolution and repli-cability in research studies and predicting berry-derived wine chemistry in commercial production.