Then you swirl it, not necessarily to smell or aerate, but to observe its viscosity.
Begin with your eyes. Sure, it’s pretty obvious that a wine is white, red or rosé, but did you know color reveals the age as well? Whites actually gain color after only a few years, oxidizing like an apple to a delicious, golden tint. But, over time, reds lose their purple, burgundy-ness as the pigment degenerates to black, sludgy sediment. The color transforms into a warm, rusted brown that appears where the wine kisses the edge of the glass. Then you swirl it, not necessarily to smell or aerate, but to observe its viscosity. In mega-alcoholic or sweet wines, the liquid forms “tears” or “legs” after it’s spun and the slower the droplets flow down the sides, the richer and fuller bodied the wine will taste.