BURGUNDY — A study on oxygen transfer through wine corks was published in 2026 in Science Advances by a team from the University of Burgundy. Thomas Karbowiak, a chemist at the university in France, served as the senior author of the study.

The study utilized an experimental setup that mimicked the cylindrical geometry of a commercial wine bottleneck. Small glass vials were sealed with scaled-down cork stoppers, with lengths ranging from 6 to 42 millimeters. The research team loaded half of the vials with model wine, while the other half remained empty, and equipped them with sensors before allowing them to age for 18 months.

Researchers identified four distinct stages of oxygen transfer through the cork. The initial phase of oxygen transfer occurred during the first 15 days after corking. During this period, dissolved oxygen in the liquid phase reached an equilibrium with the gas phase, with oxygen escaping back to the gas phase. Julie Chanut, a researcher at the University of Burgundy, described this as "It was an equilibration between the liquid phase of the model wine and the gas phase."

For the first six months, the majority of oxygen entering the wine originated from the cork itself, diffusing out of its microscopic cellular spaces. Vials sealed with longer corks received more oxygen because these corks contained a greater amount of trapped oxygen compared to shorter ones. Around four months into the experiment, the cork began to interact chemically with the wine.

In vials where the model wine was in contact with the cork, the liquid acted as a solvent, extracting phenolic compounds such as gallic acid, ellagic acid, and protocatechuic acid from the cork. These extracted compounds then reacted with oxygen released from the cork, a process catalyzed by trace metals like iron and copper. This reaction resulted in a decrease in the wine's oxygen content.

After 15 months, the wine entered a fourth phase during which external oxygen steadily permeated through the cork. By the 18th month, the rate of oxygen transfer remained low in vials sealed with corks longer than 30 millimeters. Karbowiak stated, "Twenty years ago, our group focused on the oxidation and aging of wine and all its parameters," adding that oxygen diffusion through cork stoppers is one of those parameters. He added, "Because we used model wine in the experiment and focused on oxygen transfer, we didn't do any tasting tests."