Impact of sequential inoculation timing on the quality of wine fermented by indigenous Lachancea thermotolerans and Saccharomyces cerevisiae

Abstract

Lack of acidity in wine is one of the main challenges in warm wine-producing regions. The non-Saccharomyces yeast, Lachancea thermotolerans (LT), is well known for its great potential in wine acidification through the production of lactic acid. In this study, an indigenous LT strain was sequentially inoculated with S. cerevisiae (SC). The influence of the timing of SC inoculation on wine quality was extensively studied. Inoculating SC 72 h after the inoculation of LT delayed the peak of fermentation rate, but had no significant influence on the duration of fermentation. The late inoculation (72 h) of SC effectively increased the production of lactic acid, which consequently increased the total wine acidity and decreased the pH. Higher levels of esters were also achieved by the late inoculation. Pilot-scale fermentations were carried out with both Chardonnay and Cabernet Sauvignon to verify the effect of late inoculation. Lactic acid produced in sequential fermentation was 2.73 g/L for Chardonnay wine and 5.35 g/L for Cabernet Sauvignon wine, and the production of ethyl esters was also enhanced. Overall, the results demonstrated that the late inoculation of SC in sequential fermentation with LT improved wine quality by increasing acidity and producing more balanced and aromatic wines.