A full factorial study on the effect of tannins, acidity, and ethanol on the temporal perception of taste and mouthfeel in red wine

Wine is a globally appreciated alcoholic beverage, with complex sensory properties. Ethanol, acid and tannin play a primary role in the aroma, taste and mouthfeel perception of wine, and ultimately on product liking. This study utilized a factorial design to explore the relationship among these factors in Merlot wine. The design encompassed three acid concentrations: 5, 6, 7 g/L tartaric acid eq., three ethanol concentrations: 14, 14.5, 15% (v/v), and two tannin concentrations: low (approx. 700 mg/L CE), and high (approx. 1200 mg/L CE). The 18 wines were achieved through post fermentation additions of tartaric acid and water. Descriptive analysis (DA) and temporal dominance of sensation (TDS) were applied to profile static and temporal sensory perception. Descriptive analysis (DA) was used to asses 16 aroma, 4 mouthfeel, and 3 taste attributes. The evaluated factors showed no impact on the 16 aroma descriptors. Tannin concentration showed the greatest impact on taste and mouthfeel, significantly increasing sourness, bitterness, astringent texture, drying, and overall astringency. Acid concentration significantly increased the perception of sourness, while decreasing bitterness. Ethanol concentration was not a significant source of variation within the descriptive analysis. A novel way of analyzing TDS curves was applied, based on the factorial design, which allows for the temporal effect of specific factors to be studied. Wines were grouped by factor followed by TDS curve construction. Both normalized and standard TDS curves were constructed. Normalization captured the initial dominant perception, while standardized curves show the decline in dominance as the evaluation proceeds. Overall, the data demonstrates the dominance of astringency over multiple red wine taste factors.