Understanding aroma loss during partial wine dealcoholization by vacuum distillation

Abstract

Dealcoholization of wine has gained increasing attention as consumer preferences shift toward lower-alcohol or alcohol-free beverages. This process meets key demands, including health-conscious lifestyles, regulatory compliance, and the expanding non-alcoholic market [1-3]. While traditional winemaking naturally produces alcohol, dealcoholization techniques reduce its content while preserving wine’s sensory and chemical integrity. Various methods, such as membrane processes, reverse osmosis, spinning cone column technology, and thermal distillation [4], offer different advantages and challenges, particularly regarding wine volume loss, aroma retention, and overall quality. Among these, vacuum distillation (VD) is promising for partial or complete dealcoholization by operating at lower pressures and temperatures.

This study investigates VD for partial dealcoholization (~2°). First, in a model wine, we analyze the impact of VD parameters—including number of columns, column packing type, and pressure—on aroma variation. Second, we evaluate VD’s effect on the chemical composition and sensory profile of white, rosé, and red wines using a selected VD setup.

The analysis of VD in model wine shows that higher alcohols are partially lost in the distillate (59–78% v/v ethanol), with 35% reduction for 2-methylpropanol and 3-methylbutanol, while methanol loss remains minimal (~2%). Aldehydes exhibit higher loss rates, with 60% loss for ethanal and 80% for ethyl acetate. Esters show 74–99% loss, depending on type. Results indicate that pressure significantly impacts aroma retention: lowering the pressure from 150 mbar to 50 mbar enhances ester retention, while 150 mbar increases higher alcohol and aldehyde removal.

In wines, partial dealcoholization (~2°) extracts mostly ethyl acetate (~90%), small amounts of methanol (1–10%), and 20–40% of higher alcohols. Larger esters (C8+ and cyclic esters) are less affected by VD, suggesting their lower volatility helps retain them in the wine, preserving some aromatic complexity. However, 80–100% of short-chain (C2–C4) and medium-chain (up to C6) esters are lost in the distillate, significantly altering the wine’s aroma. These esters exhibit high Henry’s law constants, explaining their volatility and major impact on wine aroma.

To conclude, even at the early stages of dealcoholization (~2° reduction), most wine aromas are lost in the first distillate fraction, highlighting the challenge of preserving fruity notes while separating them from ethanol.

References

[1] Ohana-Levi, N.; Netzer, Y. Long-Term Trends of Global Wine Market. Agriculture, 2023, 13 (1), 224. https://doi.org/10.3390/agriculture13010224.

[2] Anderson, B. O.; Berdzuli, N.; Ilbawi, A.; Kestel, D.; Kluge, H. P.; Krech, R.; Mikkelsen, B.; Neufeld, M.; Poznyak, V.; Rekve, D.; et al. Health and Cancer Risks Associated with Low Levels of Alcohol Consumption. Lancet Public Heal., 2023, 8 (1), e6–e7. https://doi.org/10.1016/s2468-2667(22)00317-6.

[3] Tempere, S.; Pérès, S.; Espinoza, A. F.; Darriet, P.; Giraud-Héraud, E.; Pons, A. Consumer Preferences for Different Red Wine Styles and Repeated Exposure Effects. Food Qual. Preference, 2019, 73, 110–116. https://doi.org/10.1016/j.foodqual.2018.12.009.

[4] Sam, F. E.; Ma, T.-Z.; Salifu, R.; Wang, J.; Jiang, Y.-M.; Zhang, B.; Han, S.-Y. Techniques for Dealcoholization of Wines: Their Impact on Wine Phenolic Composition, Volatile Composition, and Sensory Characteristics. Foods, 2021, 10 (10), 2498. https://doi.org/10.3390/foods10102498.