Scientists map oxygen’s slow leak through wine corks

oxygen transfer – In France’s Burgundy, researchers recreated wine bottles with corks of different lengths to track how oxygen moves and reacts over time. The study, published in Science Advances, shows oxygen exposure unfolds in overlapping physical and chemical stages—first b

For years. winemakers have treated oxygen like a quiet force you can’t fully see—but you feel it in the glass. Too little and a wine may struggle to develop; too much and it oxidizes early. flattening aromas and. in extreme cases. turning white wine brown. The problem is that oxygen doesn’t rush into a sealed bottle. It arrives slowly—yet no one has been able to watch all the steps at once.

At the Food and Wine Science & Technology laboratory in the heart of France’s Burgundy wine region. researchers have built an unusually direct way to study that slow intrusion. Their work focuses on a central question in modern enology—the science of wine and wine making: how does oxygen slowly enter a sealed bottle over time?.

The study, published on Friday in Science Advances, tackles a stubborn gap. In recent years. researchers have identified several distinct mechanisms governing how oxygen moves and reacts inside a bottle. but studying all of those processes for a single bottle of wine has proven difficult. This new effort tracked each mechanism simultaneously. revealing how a bottle’s oxygen exposure changes from its first days after bottling through years of storage.

The team’s attention landed on the cork—often ignored once the bottle is sold. “Usually, people don’t pay attention to the cork stopper,” says Julie Chanut, the study’s lead author and a researcher at the Food and Wine Science & Technology lab. “You open your bottle of wine, and you just throw it.”

But in the researchers’ view, cork is not just a plug. Cork is 80 to 85 percent air, acting as both a barrier and a participant in a chain of physical and chemical interactions inside the bottle.

To watch those interactions unfold, the researchers built miniature bottle systems fitted with corks. “The challenge is time. ” says the study’s senior author Thomas Karbowiak. a professor at the Institute Agro Dijon in France. “We face the particular case of a product without a shelf life. which means we have to study over a very long time. sometimes. to see something.”.

So they adjusted the experiment itself. The researchers varied the lengths of the corks. Oxygen travels more quickly through shorter corks than longer ones. allowing the team to observe mechanisms that often play out over vastly different periods—sometimes as long as multiple years—within an 18-month experiment.

What they found starts quickly and then changes character. In the first few days after bottling. oxygen quickly redistributes between the air trapped above the wine and the wine itself. eventually reaching a balance. Over the following months, oxygen stored inside the cork gradually diffuses into the bottle.

Then the chemistry shifts. Compounds from the cork dissolve into the wine and react with the available oxygen in the bottle, consuming some of it and causing oxygen levels to decline. Only over the longest time horizons does oxygen from outside the bottle slowly permeate through the cork.

The picture that emerges is not a single, steady “oxygen leak,” but a succession of overlapping physical and chemical events. The sequence matters because it explains why oxygen exposure can “make or break” a wine: the moment-to-moment chemistry is tied to what oxygen is doing. where it is coming from. and what it encounters along the way.

Those findings could help both winemakers and cork manufacturers better predict how a wine will age. Different wines are intended to be stored over different time periods—some are meant to be consumed within months of bottling. while others may spend decades in a cellar—and controlling oxygen exposure is critical to preserving flavor and aroma.

The work also lays bare how much is still unknown. Cork is a biological material whose properties change as it absorbs moisture and ages. potentially altering how oxygen moves through it. And while the study maps oxygen transfer through time. the researchers say the next challenge is understanding how the material itself evolves over years of contact with wine.

wine oxygen transfer cork chemistry Science Advances Burgundy Food and Wine Science & Technology laboratory Julie Chanut Thomas Karbowiak Institute Agro Dijon