Evaluating Lachancea thermotolerans Yeast Strains and Timing of Saccharomyces cerevisiae Sequential Inoculation on Chambourcin ( Vitis Hybrid) Wine Quality

Abstract Using non-Saccharomyces yeasts such as Lachancea thermotolerans (LT) during fermentation can enhance wine quality, including pH reduction. Two vintages (2023 and 2024) of Arkansas-grown Chambourcin (Vitis hybrid) grapes were harvested for seven inoculation treatments, in duplicate, conducted using Saccharomyces cerevisiae (SC) and three LT strains, including a commercial strain and two experimental strains (LT1 and LT2), receiving sequential SC inoculations after 24 or 48 h. The LT wine compared to SC wines in both vintages had lower pH with LT1 (24 and 48 h) and LT2-SC-48 producing more lactic acid (3.58–4.99 g/L) compared to SC (2.53–2.79 g/L). Ninety volatile compounds were identified in 2023 and 85 in 2024 with 10 compound classes composed of acetals (1), acids (10), alcohols (20–22), aldehydes (7–10), esters (29–33), glycols (1), lactones (1), ketones (10–11), terpenes (2–3), and sulfides (1), with alcohols and esters as the dominant classes. L. thermotolerans sequentially inoculated using S. cerevisiae can increase acidity and enhance aroma complexity in wines, depending on the sequential SC inoculation timing.