Enhanced Apple Cider Fermentation by Selective Light Exposure

Fermentation represents a large segment of post-harvest agricultural processing nationwide. Virginia is a leading state in the production of apples and has shown significant growth in the area of hard cider production. Consumer preference drives the hard cider market and new hard ciders are being introduced frequently. In an effort to enhance the quality of hard cider, this project sought to understand the effect of selected light (color and intensity) exposure during fermentation of apple cider on color and sensory characteristics of the resulting hard cider. Apple juice was inoculated with Saccharomyces cerevisiae and placed into a vertical glass fermentation vessel. Light of selected colors (red, yellow, green, blue, and ultraviolet) and intensities (low, medium and high) was applied to the apple juice during fermentation. Juices were allowed to ferment for 187 ± 3 h, followed by sensory and color analysis. Hard cider exposed to ultraviolet light during fermentation was most different from the dark control (fermented with no light exposure) and most preferred by sensory panelists on the basis of taste. Ultraviolet light-treated ciders were less yellow in color as compared to the dark control. Modifying the color and intensity of light may yield hard ciders with improved sensory characteristics and provide cider makers with processes to enhance quality of traditionally fermented products. This project was funded by a grant from the Virginia Agricultural Council.