L-Lactic Acid

L-Lactic AcidL Lactic acid is the second most sour organic acid in wine that is most commonly associated with the tartness of sour beers, but that is also becoming increasingly relevant for winemakers in the context of climate change (Amerine et al. 1965). While lactic acid is generally associated with biological deacidification during malolactic fermentation (MLF), yeasts like Lachancea thermotolerans are becoming increasingly common for biological acidification

L-Lactic acid is the second most sour organic acid in wine that is most commonly associated with the tartness of sour beers, but that is also becoming increasingly relevant for winemakers in the context of climate change (Amerine et al. 1965). While lactic acid is generally associated with biological deacidification during malolactic fermentation (MLF), yeasts like Lachancea thermotolerans are becoming increasingly common for biological acidification in musts by converting glucose and fructose to lactic acid before fermentation (Vicente et al., 2021). Biological acidification is very effective, capable of raising the titratable acidity upwards of 4 g/L, but also difficult to execute with precision as it is a biological process. Winemakers experimenting with Lachancea thermotolerans should note the differences in perceived sourness between Tartaric acid and Lactic acid in the resulting wines. 

Quantifying lactic acid has applications in both grapes and wine. Even though it’s not naturally occurring in grapes, UC Davis researchers suspect lactic acid testing throughout the ripening period is a useful metric for quantifying spoilage pre-harvest. Similarly in wine, it serves as an indicator of Lactic Acid Bacteria (LAB) activity, characterizing the start and progression of MLF. 

To learn more about L-Lactic Acid and its importance in winemaking, become a Bound advising client.