Hargrave Column: Why does my wine smell like caramel?

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One of the great pleasures I get from wine comes from trying to decode the aromas and flavors in each wine. To me, behind every wine there’s a mystery to be solved. As a former grape grower and winemaker, I have tasted grapes at every stage as they ripen and morph into wine. It’s tremendous fun to psych out a wine; the payoff is that if a wine is unpleasant, at least I can entertain myself by guessing what went wrong … before pouring it down the drain.

With a few organoleptic guidelines, you, too, can begin to play the wine mystery game. 

First of all, do your hands have a lingering aroma of soap, lotion, perfume or Purell? If so, wash them again without soap. Do the same with your wine glass if it, too, is contaminated by the outrageously strong aromas (“beachy breeze,” “ocean surf”) used in today’s dishwashing soaps.

Filling about a third of the glass, grasp the stem and swirl the wine in a counter-clockwise motion. This will mix the volatile aromas with air so they leap out of the glass (if the wine has an aroma; don’t expect much from pinot grigio).

Put the glass directly under your nose and inhale deeply. Always judge your first smell, since you will become acclimated to it very quickly. (Ever notice how people can be overly-perfumed without apparently knowing it?)

With practice, you can teach yourself the distinguishing qualities of grape varieties so you will be able to separate those characteristics from other fermentation-derived aromas. Sauvignon blanc is one example that demonstrates not only varietal qualities, but also fermentation decisions. It contains pyrazines with the same distinctive aroma as green bell peppers. Depending on your DNA and your bodily rhythms, you may love, hate or fail to detect pyrazines. In New Zealand, the cool climate and strong ultraviolet radiation pump up the pyrazines; the Kiwis successfully market their wines by affectionately lauding the smell of “cat’s pee on a gooseberry bush.” To emphasize the pyrazines, they ferment under cool temperatures, using inert gas to protect the juice from oxidation.

In Bordeaux, sauvignon blanc is also the dominant grape for white wines, but the Bordeaux tradition usually involves some barrel aging. Although the barrels aren’t intended to add any oak flavors, these wines are subjected to more oxygen and so the pyrazine aspect is less noticeable.

Some winemakers looking to emphasize the varietal character of their sauvignon blanc wines may deliberately trap similar sulfide fermentation odors that are formed if yeast lacks nutrient. If your wine smells more like burned rubber than green peppers, that’s hydrogen sulfide. Not sure if the smell is from the grape or the fermentation? Put a copper penny in the glass. If the smell goes away, it was from hydrogen sulfide, not pyrazine. See? Good party trick.

There’s another sulfur aroma you may detect on the first whiff: If you get a sharp, burned-match smell, that’s from sulfites (not sulfides) used to stabilize the wine. Expect more in sweet wines because they are at risk of re-fermenting and need more protection. In older wines, sulfites are less pronounced because they bind to other substances over time.

Have you ever had a white wine that smelled like butterscotch? That’s diacetyl. It comes from the breakdown of dead yeast (lees) after fermentation, especially if the wine has had a “secondary” or malolactic fermentation. To soften, stabilize and make wine more complex, bacteria are often encouraged to consume the natural malic (apple-y) acid in the wine, converting it to the less-tart, more creamy lactic acid. Diacetyl is formed as a by-product. To get rid of it, the winemaker may leave the wine on the lees, stirring it periodically over the winter until it evolves into a less-intrusive quality.

Caramel and vanilla aromas may come from barrels made from oak staves that have been aged outdoors for two to three years, until fungi break down some of the structure in the wood into sugars that are literally caramelized when the barrel is “fired” as the staves are bent into shape. A charred or barbecued aroma is also the result of coopering. Vintners pay a premium for French oak barrels that make the wine smell like caramel custard.

In my next column, I will help you to identify nasty aromas and flavors. Meanwhile, happy sniffing.

Ms. Hargrave was a founder of the Long Island wine industry in 1973. She is currently a freelance writer and consultant.

(Photo credit: icekitty37/freeimages.com)