The rheological properties of Slovenian wines Original Research Article

Forty samples of bottled wines from Slovenia were characterised by standard chemical analysis. The effect of temperature on their density and viscosity was studied in the temperature range from 20°C to 50°C. From the density data the expansibility coefficients at 25°C and their temperature dependence were calculated. The viscosity of wine decreases non-linearly with increasing temperature. The experimental data were fitted to some theoretical models in order to describe the temperature dependence of the viscosity of wine. A modified Andrade equation was found to best describe this dependence. The activation energy for viscous flow of wine, calculated by the Arrhenius relation, varied from 18.63 kJ mol−1 to 20.25 kJ mol−1. Correlations between the activation energy for viscous flow and the concentrations of solutes other than ethanol were estimated. A significant correlation between the osmolality of wine and its viscosity was found for all wines investigated.