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Hello there! I'm Dr. Vinifera, or "Vinny" for short. Ask me your toughest wine questions, from the technical aspects of winemaking to the fine points of etiquette. I hope you find my answers educational and even amusing. Looking for a particular answer? Check my archive and my FAQs.

Dear Dr. Vinny,

Does the sugar in sweet wine diminish as it ages? I tasted two colheita Ports recently, a 1980 and a 1985, and the 1985 seemed sweeter than the 1980.

—Koorosh K., Renton, Wash.

Dear Koorosh,

No, it doesn’t. The amount of residual sugar (and alcohol) in a wine is determined during the fermentation process, when the sugar is converted to alcohol. One the fermentation finishes or is stopped, these levels remain constant.

In your case, I’m guessing that either one vintage was always sweeter than the other, or that the way the sweet notes are perceived has been altered by the wine’s aging. As primary notes fade and secondary flavors become more prominent, the appearance of sweetness in the wines can move forward or fade into the background.

—Dr. Vinny

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