SENSORY IMPROVEMENT OF DEALCOHOLISED WINES

Abstract

Interest and willing-ness to buy alcohol-free wines by customers is increasing for several years [1]. Due to the rising relevance of dealcoholised wines it is the objective of this study to contribute to a better understanding of the flavor variation among dealcoholised wines and to explore enological measures, how to improve final quality.

First a range of commercial, alcoholfree white wines were analysed by the holistic sensory method projective mapping, including a question for hedonic acceptance. Based on the combination of a non-target-HS-SPME-GC/MS analysis with sensory analysis we obtained a clustering of the wines into three groups. They were characterised by varying degrees of positive, neutral and negative olfactory notes as well as the hedonic preference of the tasters.

For a targeted sensory improvement, a dealcoholised Riesling wine was processed using various oenological methods. Sweetening with grape juice obtained from a muscat variety enhanced fruity and floral aroma, which was backed by increasing concentrations of linalool, exceeding the sensory threshold. The addition of wooden chips imitated the character of a wine aged in barrels and stimulated higher preference ratings. A further improvement was tested by initiating a malolactic fermentation in the dealcoholised wines as well as a secondary alcoholic fermentation from 0 to 0.5 % vol. alc.. As dealcoholised wines lacks generally in body, mouthfeel and freshness due to the loss of ethanol, we explored the ability of yeast mannoproteins, carbonisation and prolonged yeast contact to improve these deficits. These variants were subjected to a descriptive analysis by a trained panel. It turned out that the tasters prefer-red wines with fruity and floral aroma, as well as a sweet, full-bodied taste. The use of grape juice as a sweetener, in combination with the ß-glycosidase activity to further release bound aroma compounds, as well as use of oak chips were the most successful treatments.

Modification of aroma compounds were investigated using a target HS-SPME-GC/MS-method for major wine aroma compounds. Fruity aromas were mainly linked to high concentrations of esters such as ethylbutanoate and ethylhexanoate and the floral notes with linalool and 2-phenylethanol. Especially addition of a grape juice instead of sucrose as well as use of ß-glycosidases yielded superior concentrations and sensory perception.

1. Deutsche Presse-Agentur (2021), „Bier, Wein oder Gin: Alkoholfreie Alternativen sind im Trend“, Die Zeit, 05.08.2021, available at https://www.zeit.de/news/2021-08/05/bier-wein-oder-gin-alkoholfreie-alternativen-sind-im-trend (accessed on 4. September 2022).