1, red wine hanging cup is not good, can hang the cup, hang the cup for a long time means that the wine is more dense, higher alcohol content, and is not a reflection of the quality of wine standards.

2, because the liquid on the wall of the cup has a larger surface, the alcohol evaporates more, causing a decrease in concentration. Water than alcohol in the unit surface in contact with the glass wall of the surface energy is high, alcohol concentration fell, the surface energy will increase. Liquid film to overcome gravity, the energy of spontaneous rise from the water in contact with the glass wall to release the surface energy.