Is there ever a need to decant a sweet wine?

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Dear Dr. Vinny,
Is there ever a need to decant a sweet wine? I recently had a bottle of 1995 Château d’Yquem and the sommelier served it from a decanter. I’ve enjoyed a number of high-end sweet wines before, but never saw them decanted.
—M.M., Westfield, N.J.
Dear M.M.,
It’s unusual to decant a dessert wine, but that doesn’t mean it’s a bad idea. A good sweet wine—like the d’Yquem—will certainly open up and become more expressive with air, so it’s a good call by the sommelier to serve it that way.
One thing to keep in mind when decanting a white dessert wine would be maintaining the wine’s chilly temperature to enjoy it, and decanting might warm up the wine faster than not. Another concern would be that older wines—no matter if they’re sweet, red or white—sometimes start to fade quickly when they’re exposed to air. If you’re not sure if this might be the case, before decanting I suggest opening the bottle and taking a taste. If the wine is showing intense nutty or Sherry-like flavors, it might be on the over-the-hill side and best to consume without decanting.
—Dr. Vinny