Effect of ethanol, dry extract and glycerol on the viscosity of wine Original Research Article

The viscosity of commercial red and white dry and sweet wines as well as model aqueous ethanol and glycerol solutions was measured with a falling ball viscometer. The dynamic viscosity values for NEMEA, NAOUSA, SANTORINI and MANTINEIA, four Greek “Appelation d’Origine Controllè” (AOC) wines, at 16 °C was found equal to 1.92 ± 0.05, 1.88 ± 0.07, 1.80 ± 0.07, 1.71 ± 0.02 mPa s, respectively. The dynamic viscosity values for the sweet wines AOC MAVRODAFNI and AOC SAMOS was found equal to 3.04 ± 0.1 and 3.16 ± 0.1, respectively. The decrease in viscosity with increasing temperature was adequately described by the Arrhenius equation with activation energy ranging between 21.92 and 22.48 kJ/mol. Alcohol content and dry extract were identified as the two factors that mainly influence the viscosity of the wine, while glycerol has a negligible contribution due to its low concentration. A multiple linear model describing first order effects of ethanol, dry extract and glycerol on the viscosity of the wine was fitted to the experimental results.