Q. When should wine be decanted, and what’s the purpose of doing that?
A. The number one reason for decanting is to separate a wine from the sediment that often forms in bottles of older red wines. I have yet to meet a person who enjoys the sensation of chewing a mouthful of grit while sipping fine Bordeaux.
Decanting has an additional benefit, which can also become a curse—it aerates the wine, opening up dormant aromas and flavors but also starting the wine on a downhill slide. Some wines deteriorate very slowly; others quickly. For young, highly tannic wines, such as Barolo, Petite Sirah and some Cabernets, decanting and then allowing the wine to breathe for up to an hour can make it more agreeable. Older and more delicate wines may lose their luster in a hurry. Decant old versions of the big reds just mentioned immediately before serving. And no matter how anxious you are to break out that beautiful decanter, I’d recommend using it as a centerpiece before allowing it to diminish the subtle and ephemeral pleasures of red Burgundy, Pinot Noir and very old Rioja.
—By Charles Smothermon, a wine expert living in Lauren, Mont.