The use of L. thermotolerans to acidify wine is of particular interest for wines produced from grapes grown in warmer climates with high sugar content and low organic acid content. Traditionally, the problem of low acidity would be addressed by the addition of tartaric acid , but this is costly and can affect the quality of the wine . In 2021 Hranilovic, et al. built on their previous work with L. thermotolerans to study the impact of this yeast on the chemical composition and sensory properties of Merlot wines. The authors carried out fermentations with five L. thermotolerans strains in co-inoculated and sequentially inoculated ferments with S. cerevisiae. HPLC was used to measure glycerol, lactic acid, malic acid, and acetic acid, while HS-SPME GC-MS was used to assess the presence and concentration of volatile secondary metabolites in the finished wines. Sequential ferments using first S. cerevisiae then L. thermotolerans resulted in the lowest ethanol and highest lactic acid concentrations, but co-inoculation of S. cerevisiae and L. thermotolerans still produced moderate amounts of lactic acid. Strain differences between the lactic acid production of different L. thermotolerans strains was also observed. A total of 31 volatile compounds were identified in the wines, which were predominantly yeast-derived metabolites . These metabolites included ethyl esters, acetate ester, higher alcohols, organic acids, and linalool. Ethyl acetate and ethyl lactate, which both contribute to 'fruity' aromas and complexity in wine, were the predominant esters in the wines. The S. cerevisiae monoculture wine had the lowest concentration of ethyl acetate, with up to 2.5 times higher concentrations found in sequential fermentations. These higher concentrations did not, however, exceed the threshold at which ethyl acetate becomes undesirable rather than contributing 'fruity' complexity.