A Glass of Wine

Water is so-called polar liquid (its molecules have strong electric dipole moment) and it has a high coefficient of surface tension. This coefficient drops only slightly with the rise in temperature, from 75.6 units (dyn/cm) at 0 °C to 69.6 units (at 40 °C). However, it drops considerably when water is mixed with other liquids.

Adding small amount of, for example ethyl alcohol, considerably lowers surface tension. Thus, 10% of alcohol (as in a white wine) reduces surface tension to 48.25 units (at 40 °C) and 24% (as in liqueur) - to 35.5 units.

Surface tension for given liquids can be assessed upon observation of the shape of their drops on a clean glass plate (see the picture).
The surface tension determines also the velocity of the waves propagating on the surface of liquids. Therefore, as shown here, the pattern of waves changes in wine as compared to water. This in another method for checking if the wine is good.