Sustainable strategies to ensure reliable alcoholic fermentation under climate change–driven alterations of grape must composition

Abstract

Reliable alcoholic fermentation is essential for the production of high-quality wine and sparkling wine. Small and medium-sized wineries are increasingly affected by fermentation problems, which can lead to substantial economic losses. In addition to insufficient yeast viability and vitality, climate change–induced alterations in grape and must composition represent major risk factors. Elevated sugar concentrations, reduced yeast-assimilable nitrogen, altered pH values, and increased ethanol levels impose stress on yeast cells, significantly increasing the risk of sluggish or stuck fermentations. Against this background, the EFMoST project adopts an integrated approach to improve fermentation reliability by combining optimised rehydration and propagation strategies for active dry yeasts with adaptation measures addressing climate-related changes in must composition [1]. A central focus is the development of simple, scalable, and OIV-compliant methods for controlled aerobic yeast propagation to obtain highly vital and metabolically active yeast cultures [3]. In parallel, practical and cost-effective methods for assessing yeast viability and vitality are being developed to enable fermentation fitness to be evaluated directly in the winery [3]. Complementary to this, the VINO-KLIM project systematically investigates the effects of climate change on grape must and base wine composition, with particular emphasis on yeast-assimilable nutrients and their impact on fermentation performance [4]. Based on these analyses, the fermentation behaviour of different wine yeast strains is studied under nutrient-limited and ethanol-stressed conditions to identify robust strains and critical nutrient thresholds [5]. In addition, photometric rapid tests are being developed to support the rapid assessment of key must parameters and targeted nutrient supplementation [6]. By integrating optimised yeast preparation, adapted analytical tools, and a deeper understanding of climate change–induced changes in must composition, these projects aim to establish practical strategies to prevent fermentation failures and to support more resilient and sustainable wine and sparkling wine production.

References

[1] C. van Leeuwen et al., “Climate change impacts and adaptations of wine production”, Nat Rev Earth Environ, vol. 5, no. 4, pp. 258–275, 2024, doi: 10.1038/s43017-024-00521-5.

[2] P. D. Hellín, J. Úbeda, and A. Briones, “Improving alcoholic fermentation by activation of Saccharomyces species during the rehydration stage”, LWT – Food Science and Technology, vol. 50, no. 1, pp. 126–131, 2013, doi: 10.1016/j.lwt.2012.06.011.

[3] M. Kwolek-Mirek and R. Zadrag-Tecza, “Comparison of methods used for assessing the viability and vitality of yeast cells”, FEMS yeast research, vol. 14, no. 7, pp. 1068–1079, 2014, doi: 10.1111/1567-1364.12202.

[4] R. Mira de Orduña, “Climate change associated effects on grape and wine quality and production”, Food Research International, vol. 43, no. 7, pp. 1844–1855, 2010, doi: 10.1016/j.foodres.2010.05.001.

[5] A. Gutiérrez, R. Chiva, M. Sancho, G. Beltran, F. N. Arroyo-López, and J. M. Guillamon, “Nitrogen requirements of commercial wine yeast strains during fermentation of a synthetic grape must”, Food microbiology, vol. 31, no. 1, pp. 25 32, 2012, doi: 10.1016/j.fm.2012.02.012.

[6] Di Nonno, S.; Ulber, R. Portuino—A Novel Portable Low-Cost Arduino-Based Photo- and Fluorimeter. Sensors 2022, 22, 7916. https://doi.org/10.3390/s22207916

Funding

The EFMoST project is funded by the Landwirtschaftliche Rentenbank within its research programme for innovation in agriculture (Funding code: 1 012 183). The VINO-KLIM project is co-funded by the European Commission and the State of Rhineland-Palatinate (Funding code: P1-SZ1-9 InnoProm – MWG).