I have often heard people describe some wines as having long legs. They swirl the wine in the glass and watch the streaks running down the sides of the glass. The remark is usually, “Oh, long legs, good quality”. Does the length of the legs really help determine quality? I have some wines I thought were great and the legs barely stayed on the glass.
The legs actually do not determine quality. The legs help to determine the alcohol content of the wine. The longer the legs last, the higher the alcohol content. The phenomenon is referred to as “Tears of Wine”. It starts as a clear ring of liquid near the top of the glass. Droplets form continuously from the ring and drop back into the wine. The longer these tears cling to the side of the glass, and the more of them there are, the higher the alcohol content. Besides legs and tears, I have heard the droplets called curtains and church windows. Sweeter wines are more vicious as the tears (legs) will flow slower down the sides of the glass. If you want to get into the sciences of this, Google the Gibbs-Marangoni Effect, as it will explain the mechanics of this phenomenon and why covering your glass will make the tears (legs) disappear.
It is a myth that legs determine quality. Legs are a guide to alcohol content. However, I do have some friends that believe higher alcohol does mean higher quality. The length of legs might be a quality you look for in a date, but they do not tell you the quality of the wine.
For those of you, who really want to know the alcohol content of wine, let me know. I have a friend who can determine the alcohol by volume after three sips! She does not need to see the legs. I usually just cheat and read the label.
So, you may still be wondering why wine drinkers swirl the wine in the glass. The swirling helps to release the aroma molecules from the wine which in turn improves the ability to better smell and taste the wine. The swirling action increases the surface area of the wine, which then increases the oxygenation of the wine, thus affecting the flavor. But at the end of the day, some wine drinkers still like looking at the legs even if they know they don’t mean a thing when it comes to quality!
Hoosier Wine Guy