Impact of fermentation-temperature management combined with specific yeast choice on energy savings in white winemaking

¹ Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, Università degli Studi di Milano, Via Celoria, 2, 20133 Milan, Italy
² Department of Biomedical, Surgical and Dental Sciences - One Health Unit, Università degli Studi di Milano, Via Mangiagalli, 25, 20133 Milan, Italy
³ CREA, Council for Agricultural Research and Economics, Research Centre for Viticulture and Enology, Viale XXVIII Aprile 26, 31015 Conegliano, Italy

^* Corresponding author: tiziana.nardi@crea.gov.it

Abstract

Heat removal significantly impacts energy request in the winery and is related to the temperature control of wine tanks during the fermentation process and the wine maturation phase. The aim of this work was twin: first, to determine the heat dissipated from tanks under different temperature fermentation programs, to evaluate the impact of temperature management combined with specific yeast choice on energy saving during industrial-scale (450 hL) white vinification. Second, to explore the applicability of such protocols, and the extent of the potential effects thereof, through a survey. Comparative winemaking tests were carried out by using properly chosen yeasts during fermentation of Glera and Pinot Grigio musts at usual winery temperature (15 or 17-15 °C) and 19 °C, verifying the quality of the resulting wines in term of sensory, chemical and aromatic features. Fermentation required on average 7.0 Wh dm-3 at 19 °C and 10.3 Wh dm-3 must at 15/17-15 °C, reducing energy use by ~32% at the higher temperature, without compromising sensory, chemical, and aromatic profiles of wines. Then, the potential widespread of those effects was investigated through a survey involving several (n>100) wineries: among others, questions about vinification volumes, usual fermentation temperatures and attitude towards energy-saving innovations were asked to winemakers. Our results suggest that wineries can adopt a more sustainable winemaking process with low energy consumption and that this choice may have a relevant impact on white-winemaking energy consumption in the Italian context. Indeed, ~70% of a sample of winemakers representing an overall production of 1.300.000 hL, declared a willingness to increase their usual fermentation temperature if research data support energy-saving expectations without compromising wine quality.