The Enduring Appeal of Cork in the Wine Industry

Until the mid-1990s, virtually every bottle of wine was sealed with a cork. Despite attempts to introduce alternatives such as ROTE (roll-on tamper evident) or ROPP (roll-on pilfer-proof) aluminium closures, better known as screw caps, the wine industry was reluctant to change. That raises the question: what is the enduring appeal of cork?

Cork taint has always been a challenge for the wine industry, giving rise to the restaurant ritual of offering customers a small taste before serving. Cork taint became a significant problem, however, especially in places like Australia, which seemed to receive lower-quality corks. As the wine market expanded in the 1990s, demand for cork grew, but quality control became a bigger concern.

The turning point came in the mid-1990s with the first plastic corks. By 2000 screw caps had become popular in Australia, which quickly adopted this type of closure. So why did the wine industry stay loyal to cork for so long?

Part of the answer emerged while testing the various alternatives. Unlike spirits, wine is highly sensitive to oxidation and has complex chemistry after bottling. Sealing a bottle of wine isn't just about keeping the liquid in and the air out.

By switching to plastic corks, producers wanted an effective seal against air and liquid without the risk of cork taint. Plastic, however, lets gas diffuse through it, resulting in an oxygen transfer rate (OTR). With the first plastic corks, this meant wines could oxidise quickly, although some robust reds proved more durable thanks to their phenolic compounds.

Because of its sensitivity to oxidation, wine needs special care. Compared with many other drinks, it faces unique challenges. The secret of cork's lasting appeal seems to lie in the complexity and delicacy of wine itself, which is why the industry keeps exploring and refining closures that preserve its distinctive quality.