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Santé! Scientists in France think they've found a way to make better wine and aged whisky

Wine scientists in France, because of course there are wine scientists in France, believe they have found a simple way to make fine wines and aged whiskies taste even better.

There has always been an art and a science to the vintners’ and distillers’ crafts, even if the early science was more good luck and unwitting trial and error than fastidious study.

Scientists, however, have been sticking their noses into wines and spirits, literally and figuratively, for decades trying to figure out the complicated chemistry behind why some wines are sought-after classics while others are plonk, and how Scotch whisky made the exact same way in different places can taste starkly different.

These are among the mysteries of a libational life that, for many drinkers, are best left behind while a bottle is emptied. For wine and spirit scientists, however, these answers are essential.

Professor Axel Marchal, at the Université de Bordeaux, located in the hub of France’s wine-growing region, has the degrees and publications of a scientist, but retains an ability to appreciate the magic.

“The aim of the winemaker is not to give the taste to the wine,” Marchal said, “but to reveal the taste of the wine.”

Wine and spirits have complicated mixtures of flavours and aromas that change with time, especially through aging in wood barrels. Prolonged contact between the alcohol and the staves of the barrel, usually made of oak, creates something new.

Scientists have been taking bottles out of the pub and into the laboratory trying to better understand this interaction at the molecular level.

Marchal, for instance, got his PhD a decade ago for identifying compounds other than sugars that add sweetness to dry wines.

In a new journal article , published in the Journal of Agricultural and Food Chemistry, Marchal and colleagues tackled the problematic bitter qualities in wines and spirits.

Among the many components swirling around where alcohol and oak meet are coumarins, an obscure compound found in many plants that help them defend against pathogens.

Coumarins are mostly bitter, which is usually not an admirable characteristic in a tipple. But they are tricky to nail down, said Delphine Winstel, a post-doctoral student at Bordeaux who did the experiments for the study.

The preparation, methodology and analysis of the study is painstaking and complicated. Their discussion of the chemical structure, chromatography and tasting panels is to drinkers the equivalent of a sex ed lecture by a gym teacher for young lovers.

At the end of their research, however, there was an epiphany.

She measured concentrations of six different types of coumarins in 90 commercial wines and 28 spirits, including whisky, cognac, and rum.

As expected, the coumarin content was much higher the longer alcohol was in contact with wood, so it is most prominent in aged whisky and rum and more important for red wine than white, Winstel said.

Individually, each coumarin was found to be outside the range of human taste, but all together, their bitter qualities rang through.

The findings, they hope, will lead to better tasting wine and spirits.

It is the codification of a pleasure activity

Further research can look for ways to limit coumarin content in the wood used by cooperages, where barrels are made, perhaps through scrutiny of the origin of the oak trees or how they are toasted or charred.

“The end is to improve the product,” said Marchal.

“Oenology is an applied science; we cannot just stop when we have identified the compounds, investigating the compounds is the first step.”

The science takes the chemical view of a glass of wine or spirit.

“It is the codification of a pleasure activity,” he said.

It traces chemical changes from grapes growing in a vineyard, accounting for all of the terroir — soil, climate, topography, farming practices — through winemaking and the maturation.

“Finally, these molecules interact with the senses of the taster. We can see that the messenger of this link between the soil and the brain are molecules.”

Sometimes, tinkering with a good thing — even the smallest of things — can make it better.

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