RT Journal Article SR Electronic T1 Predicting the Impact of Fermentor Geometry and Cap Management on Phenolic Profile Using a Reactor Engineering Model JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP ajev.2019.19051 DO 10.5344/ajev.2019.19051 A1 Konrad V. Miller A1 Anita Oberholster A1 David E. Block YR 2019 UL http://www.ajevonline.org/content/early/2019/10/09/ajev.2019.19051.abstract AB Understanding of phenolic extraction during fermentation has long been limited to either empirical studies or well-mixed models, which limits the ability to predict the impact of winemaking decisions on final wine phenolic profile. We have developed a combined phenolic extraction and fermentation model by combining previously derived and validated red wine models, which accounts for the heterogeneous nature of red wine fermentations and fermentor geometry. In this work, we apply this model to explore the impact of fermentor volume and cap management on anthocyanin, skin tannin, and seed tannin extraction. Results indicate that larger, hotter fermentors favor faster extraction, with pump over frequency having a strong impact on anthocyanin and skin tannin extraction, as well as the relative contribution of seed and skin tannins. At small scales, this variation was not observed, in agreement with experiment. These results suggest potential winemaking strategies for controlling the ratio of skin to seed tannins in the final wine. Additionally, we explored the impact of the ratio of cap surface area to bulk liquid volume to be critical in determining the concentration of anthocyanins in the bulk liquid, shedding light on conflicting small and large scale results of liquid anthocyanin concentrations without cap management.