Viscosity

viscosity, the quality of being viscous, the extent to which a solution resists flow or movement. Honey is more viscous than sugar syrup, for example, which is considerably more viscous than water. Viscosity, which approximates to what wine tasters call body, can be sensed by the human palate in the form of resistance as the solution is rinsed around the mouth.

A very sweet wine is more viscous than a dry one, even if they have the same alcoholic strength. Alcohol itself is more viscous than water, and higher-strength wines are therefore more viscous than lower-strength wines. An increase of 1% in alcoholic strength increases viscosity relative to water by about 0.04 units, while an increase of 10 g/l in residual sugar increases viscosity by about 0.03 units. The most viscous wines of all, therefore, are those that are both sweet and strong.