There is an ongoing debate between using natural corks for wine bottles and the more modern practice of using synthetic corks. To truly understand this issue, it’s important to consider the significance of each argument.
The natural cork has been in use since the seventeenth century. In fact, it was first introduced by the famous champagne maker Dom Perignon. The natural cork is associated with centuries of tradition, elegance, and sophistication.
Cork comes from the bark of a specific species of oak tree found in the Mediterranean and Portugal. While these trees have an average lifespan of 150 years, the cork can only be harvested every nine to twelve years, making this resource highly valuable. The number of wine bottles produced each year continues to rise—about seventeen billion bottles annually—and natural cork production simply cannot keep up with that demand. Aside from the issue of resource availability, there is the growing concern over TCA (2,4,6-trichloroanisole). TCA is produced by fungus that grows in cork, causing great anxiety for wine lovers. It has been associated with cork taint, which affects as many as twelve percent of wine bottles produced each year.
Challenges with Synthetic Corks
In response to the issues surrounding natural cork, synthetic corks have emerged as an alternative, but not without their own concerns. Synthetic corks are used in about nine percent of annual wine production. They can be branded just like natural corks, and are often produced in various colors. However, this raises concerns about the chemicals that may be transmitted to the wine over time. Synthetic corks can be removed using a traditional corkscrew, but they are difficult to replace in the bottles due to their expansion, so a wine stopper is recommended.
Another concern for natural cork enthusiasts is that synthetic corks serve no purpose other than as a plug. Natural corks are used as tools to detect the smell and freshness of the wine. It’s impossible to determine if a bottle has been exposed to air with a synthetic cork since it lacks the natural drying fibers of a real cork. The slight air contact allowed by natural cork, though minimal, is part of the aging process for red wines. Wines with synthetic corks have been known to oxidize more quickly, making them less desirable to consumers and restaurateurs.
According to Ernie Farinias, winemaker and cellar master at the University of California, Davis, “We look at synthetic corks for wines that will be consumed within five years or less. Usually, wines destined to age for more than five years use natural cork.” This sentiment is a concern for those who have invested in wines for the long term. Wines that are corked with synthetics may not turn out to be the cellar-worthy investments their purchasers intended.
One solution to the air exposure issue—commonly associated with red wines—is to use synthetic corks for white wines, while reserving natural corks for young reds and high-quality wines. This approach is particularly common among Italian winemakers.
On the other hand, synthetic corks do not crumble or break inside the bottle, and they transmit no foreign odors to the wine. They are easy to remove, and wineries can replace natural corks with synthetic ones at no additional cost since they function mechanically in the same way. This makes them a more trouble-free alternative. With further research, scientists may develop a synthetic cork that addresses the permeability and adhesion issues currently associated with synthetic corks. There are other alternatives, such as the metal screw top and corks made from silicone and cork powder. However, these are less practical alternatives, as they are more costly to transition to and may lower the traditional quality of the cork even further.
Since the optimal conservation of wine is the goal, it is difficult to fully embrace the synthetic revolution. There simply hasn’t been enough time to determine its long-term value or effectiveness as a viable alternative to the natural cork.
