How often have you run across these phrases when you're reading a wine review: "highly structured," "crisp," "bright," "firm tannins," "fine-grained tannins."
How do they translate into your flavor experiences?
It's nothing too mysterious. "Structure" is most often used in reference to relative levels of acid (especially whites) and/or tannin (reds). But there are other things that come into play such as alcohol, sweetness and body.
Isolated, none of these components are tasty or interesting. Think of them as the framework of the wine, just waiting to be fleshed out by delicious things like fruitiness, fermentation character, oak, floral character, herbaceousness, minerality, etc.
Fortunately, Mother Nature has made it remarkably easy to detect the relative levels of the main wine components. Grab a glass of red wine and taste as we go and you'll see what I mean.
Alcohol is the only one of the main components that has an aroma, so you'll have to rely on your palate to differentiate between the rest. Using the slurping technique will really help.
For the uninitiated: Take a little sip of your wine. Taste good? Now, all you have to do is take another small sip and hold it in your mouth. Purse your lips and pull some air in through your teeth and over the top of the wine (kind of like whistling in reverse). Swish it all around your mouth, like mouthwash, and chew on it a little. Wow -- flavor explosion in your head, right? Now, we're ready to get started.
Important: All of us have different sensitivities, so you might detect alcohol more readily than I do -- I'm a cheap date. And, I might notice acid more easily than someone else.