So, what the hell is body in wine? Is that what people are talking about when they say 'this Cabernet has nice legs'? Nope. Those people are full of it. Luckily, you don't have to be; here's the low down on assessing a wine's body, or lack thereof.
The concept of body basically refers to the weight and density of a wine. It's simple: taste a wine and ask yourself on a scale of water to milkshake, where does this wine fall (i.e. how thin or thick is it)? A flippant and flowery Pinot Grigio or a lithe Pinot Noir might be light bodied, whereas an inky Aussie Shiraz or buttery California Chardonnay would be considered full bodied, and a juicy Malbec or Chenin Blanc would fall somewhere in between.
When beginning to learn about wine, something so subjective can seem difficult. Our tendency – no thanks to point scores like those given to multiple choice tests in grade school – is to make everything objective: right or wrong. This isn't the case, so don't over complicate things and judge everything on a relative scale. Does the wine feel heavy or light? If you can say, "I've had bigger," well then, you need to learn how to describe your wine in a more socially appropriate way – but on the wine front, you're probably drinking medium-bodied wine. Again, it's all relative to your personal experience.
The term body can also be used to describe a wine's structure. This is where the body analogy really begins to take shape. As you taste the wine, think of a human body type that best represents what you're feeling. Would you equate the wine to being like that of a gymnast – light, quick and graceful? If so, you could probably describe the wine similarly. Or does this wine feel more like a vinous embodiment of spokesperson Jared Fogle, pre-Subway diet – huge and kind of mushy? This is probably a heavy wine, big in body with low acidity and tannins. If something feels big, but in no way soft – think Arnold Schwarzenegger in his body building days – you'd probably articulate this wine as a big wine with a firm and hefty tannic structure.
The key is to make it your own. The best description I've ever heard about body in wine is when someone equated the body of a Riesling to a fuselage: linear and smooth, expanding in the middle, but lots of acidity that pushes it forward like an airplane.