Enhancing wine acidity through lactic and succinic acid-producing yeast strains

Abstract

Climate change presents a major challenge for the wine industry because of anticipated changes in grape composition at harvest, which include higher sugar levels (i.e., increased alcohol in wine) and decreased acidity (Gobbi et al., 2013). However, many consumers continue to prefer fresh and vibrant white wine styles (Bucher et al., 2018), which can be achieved by using novel yeasts that offer a biological solution. For example, Lachancea thermotolerans metabolism produces lactic acid with an associated reduction in alcohol levels. Selected Saccharomyces cerevisiae strains also have metabolic outputs that include increased amounts of succinic acid (Vicente et al., 2022). In this study, a Riesling must (pH 3.5, 22.3 °Brix, titratable acidity 4.69 g/L) was fermented with selected strains of L. thermotolerans and S. cerevisiae, chosen for their enhanced production of lactic and succinic acids, respectively. A commercial S. cerevisiae strain (Lalvin DV10) was used as a control. The experimental fermentations resulted in an increase in titratable acidity by 1.4 to 5.5 g/L and a reduction in pH of 0.04 to 0.28 units, depending on the yeast strain. Additionally, alcohol content decreased by 0.13 % to 0.67 % (v/v) across treatments. The L. thermotolerans strains produced lactic acid concentrations of up to 7 g/L, while one S. cerevisiae strain generated 1.4 g/L succinic acid. Sensory evaluation indicated that none of the yeast treatments led to the development of off-flavors, and significant differences in perceived sourness, bitterness, and sweetness were observed. These findings highlight the potential of bioacidification as a viable alternative to chemical acidification, particularly for producing wines with elevated freshness. Such wines may be used as blending components or as base wines for sparkling wine production where higher acidity is desirable. This strategy offers a practical tool for mitigating the enological impacts of climate change, and future research should explore optimal conditions, methodologies, and yeast selection to expand its applicability.

References

Gobbi, M., Comitini, F., Domizio, P., Romani, C., Lencioni, L., Mannazzu, I., & Ciani, M. (2013). Lachancea thermotolerans and Saccharomyces cerevisiae in simultaneous and sequential co-fermentation: A strategy to enhance acidity and improve the overall quality of wine. Food Microbiology, 33(2), 271–281.

Bucher, T., Deroover, K., & Stockley, C. (2018). Low-Alcohol Wine: A Narrative Review on Consumer Perception and Behaviour. Beverages, 4(4), 82. 3. Vicente, J., Baran, Y., Navascués, E., Santos, A., Calderón, F., Marquina, D., Rauhut, D., & Benito, S. (2022). Biological management of acidity in wine industry: A review. International Journal of Food Microbiology, 375, 109726.