When wine has no legs, it means that the wine does not leave visible streaks or droplets on the inside of the glass when swirled. This phenomenon is often attributed to the alcohol content and viscosity of the wine. Legs, also known as tears, are the droplets that form and flow down the sides of the glass after swirling.
Legs are often mistakenly associated with the quality or age of the wine. However, in reality, they are not indicative of either. The presence or absence of legs is simply a result of the interplay between alcohol, water, and surface tension.
When wine is swirled in a glass, it coats the sides of the glass due to the difference in surface tension between the liquid and the glass. The alcohol in the wine evaporates more quickly than water, which creates a difference in surface tension and leads to the formation of legs. The slower the legs flow, the higher the alcohol content and viscosity of the wine are perceived to be.
However, when you swirl wine in a closed bottle, as mentioned in the question, no evaporation can take place. This airtight environment prevents the formation of legs. It's important to note that this lack of legs in a closed bottle does not indicate anything about the quality or characteristics of the wine. It is simply a result of the absence of evaporation.
Legs can be a visually appealing aspect of wine, as they can give the wine a sense of texture and body. However, they should not be the sole factor in determining the quality or enjoyment of a wine. Other factors such as aroma, taste, and overall balance should be considered.
The absence of legs in a closed bottle of wine is a natural result of the airtight environment, which prevents evaporation from occurring. Legs are not an indicator of wine quality or age, but rather a result of the interplay between alcohol, water, and surface tension. So, while it can be enjoyable to observe the appearance of wine and appreciate the presence of legs, it should not be the sole focus when evaluating a wine.