At this first step in wine tasting, a wine taster may not know what type of wine they have, but by looking at it they can identify some clues to its variety. For example, a fuller-bodied wine like a Cabernet Sauvignon is deeper in color than a lighter-bodied wine like a Pinot noir and a denser, sweeter wine like a dessert wine, such as Muscat, will leave thick, viscous “legs” or streaks running down the inside of the glass when swirled. As a taster moves along in the tasting process (evaluating overall quality) they examine the terroir of a wine – the region in which it was produced – and whether a wine has good “typicity”, i.e. how well the wine expresses or represents its grape variety.
Whether it is a red or a white wine, aging wine changes its color. Color changes occur when grape tannins and oak/wood tannins interact with other compounds to the point that they turn to sediment and can no longer stay in the wine. Aged red wines are lighter in color than un-aged red wines. The red pigments (anthocyanins) of red wine bond with the sediment, thereby removing color from the wine. Some aged white wines are a little different in that the wine becomes “oxidized” and turns the wine’s color towards brown. Actually, most white wines don’t age well and an “oxidized wine” is considered a “faulty” wine.
A wine that becomes excessively exposed to oxidation is an oxidized wine in wine tasting terminology, it’s a negative characteristic and one that gives non-sherry wines a sherry-like odor.
On the other hand, “oxidative” is a positive term describing an oxidation process that is regulated and controlled throughout the aging of a wine.
During the aging process, a wine’s “aroma” is replaced with an aged wine’s “bouquet”. An aged wine can have flavors and aromas that stretch anywhere from nutty, oaky and buttery to smoky, spicy and beyond.