Project number
IWBT W 20-01
Project leader
Dr Hélène Nieuwoudt
Institution
South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University
Project is co-funded by the Department of Science and Innovation
Project completed
2022
EXECUTIVE SUMMARY
Objectives and Rationale
Driven by the growing economic importance of the de-alcoholised wine category, this project aimed to conduct an industry-wide assessment of the sensory quality of South African de-alcoholised wines and to generate their chemical profiles, with a focus on volatile aroma compounds.
Methods
Wine industry professionals evaluated the sensory quality of de-alcoholised wines in blind tastings using a 20-point scale and free listing for sensory descriptions. Chemical analysis involved GCMS-MS for volatile aroma compounds and HPLC/enzyme-linked spectrophotometry for non-volatile compounds. Data analysis included lemmatisation, correspondence analysis, and ANOVA.
Key Results
The overall quality of most still and sparkling de-alcoholised wines was assessed as average to below average, with panellists frequently identifying sensory faults, particularly in aroma and palate. Chemical analysis revealed unusually high levels of glycerol and markedly lowered ranges of volatile aroma compounds, especially esters, compared to typical full-strength wines.
Key Conclusion of Discussion
The findings highlight several technical challenges in de-alcoholised wine production that necessitate an industry-wide workshop. Critical aspects to address include the suitability of different grape cultivars, shelf life, optimal final alcohol concentration (0.5% or 0.05% v/v) for improved sensory quality, reconstitution strategies, and the potential addition of flavour compounds.
Take Home Message for Industry
To enhance the overall quality and market competitiveness of South African de-alcoholised wines, stringent sensory quality benchmark testing against high-quality local and international counterparts is imperative, along with understanding product intrinsics. This will guide product development and foster consumer confidence in this emerging category.