Effect of<i>Lachancea thermotolerans</i>Yeast on Chambourcin (<i>Vitis</i>Hybrid) Wine Quality

<h3>Abstract</h3> <h3>Background and goals</h3> Chambourcin (<i>Vitis</i> hybrid) red wine grapes, commonly grown in the southern and eastern United States, often exhibit low acidity and high pH at harvest, posing challenges for wine quality. Fermentation with non-<i>Saccharomyces</i> yeast such as <i>Lachancea thermotolerans</i> may influence acidity and other key wine attributes. <h3>Methods and key findings</h3> In 2020 and 2021, Chambourcin grapes from Arkansas were processed into wine using four fermentation treatments: <i>Saccharomyces cerevisiae</i> with and without malolactic fermentation (SC-MLF and SC, respectively) and sequential inoculation with <i>L. thermotolerans</i> and <i>S. cerevisiae</i> with and without malolactic fermentation (LT-SC-MLF and LT-SC, respectively). Wine composition and color were evaluated at bottling and during storage at 15°C (0, 6, and 12 mo). In addition, sensory evaluations by consumers (n = 126) and by a professional descriptive panel (n = 7) were conducted on the 2020 wines. Wines fermented with <i>L. thermotolerans</i> (LT-SC) showed lower pH (3.34), higher titratable acidity (TA; 12.28 g/L), and more intense red coloration compared to SC wines (pH 3.64, TA 7.15 g/L). LT-SC wines also had higher lactic acid (5.84 g/L) and total organic acids (12.13 g/L) than SC wines (3.22 and 7.50 g/L, respectively). However, the higher acidity and organic acid levels were negatively correlated with consumer liking of sourness and overall impression, while a higher pH was associated with greater consumer acceptance. <h3>Conclusions and significance</h3> Sequential fermentation with <i>L. thermotolerans</i> and <i>S. cerevisiae</i> produced wines with improved acidity and color, but the increased sourness reduced consumer acceptability. Adjustments such as blending or sugar additions at bottling may enhance consumer appeal while retaining the desirable quality attributes imparted by <i>L. thermotolerans</i>.