The case of Screw cap v. Cork, has been vigorously debated in online forums and at wine shop counters over the last decade. Originally, the argument felt like a tennis ball volley between staunch cork traditionalists, who hoped to preserve romance and ritual, versus practical minded sommeliers and progressive marketing teams aiming to lure next-generation drinkers. One side would present pragmatic evidence to support their claim and the other would counter with relevant statistics. Back and forth it went. Alas, as debate continued, screw caps steadily gained traction with consumers and bottles sales with alternative enclosures increased across the globe.
The cork debate started small -- very small. The culprit? 2-4-6 Trichloroanisole or TCA. TCA is the compound responsible for cork taint; it’s what makes wine smell like wet cardboard or my grandmother’s couch. Not pretty. It’s powerful and can be detected by some tasters in amounts as little as 2-4 parts per trillion. (By contrast, the seats of a brand new Chrysler Sebring convertible are smelled in parts per million). Because up to 5% of bottles were affected by TCA, screw caps seemed like an attractive option. After all, imagine the disappointment of the person who has waited for the perfect moment to open that treasured bottle only to discover it’s “corked”. Not good. The cork industry responded by changing hygiene and testing practices at production facilities and levels of TCA have declined to somewhere between 1% and 2%.
While cork facilities were cleaning up their act, cork advocates went on a two-pronged offensive. First, they branded themselves as a renewable, green industry. Because the bark used in cork production is able to regenerate, no trees are cut down during the harvest. Further, they trumpeted how cork’s permeability contributes positive characteristics to bottles as they age by allowing a tiny bit of oxidation. Following suit, Amcor, producer of the industry leading Stelvin screw cap closures, introduced a series of plastic liners, which enable small levels of oxygen exposure, thus simulating the aging properties offered by cork.
Presently, white wine dominates the screw cap landscape in the US with red wine gradually gaining a foothold. It seems it’s been easier for producers and consumers to accept the role of screw caps for white wines as concern over the impact of long term aging is less of an issue. For reds, at least in France, Italy and the US, the conversion lags behind.
While difficult to determine the exact number of cases utilizing screw caps in the US, glass sales for screw cap bottles are on the rise. Globally, screwcaps sit atop some 15% of bottles, with some markets, like New Zealand, hovering closer to 90%. New Zealand-based Foley properties, Clifford Bay and Vavasour, use screw caps for all bottlings. Here, in California, Eos and Firestone, have made the switch for several white wines.
As wine producers struggle over how a cork or screw cap may impact the image of the winery, dialogue over packaging continues to evolve. Obviously, cork’s centuries long link to wine stored in glass bottles ensures it won’t be going away anytime soon. However, in recent years, concern over the possible connection between human activity and climate change has come into play. In an effort to reduce the carbon footprint while bringing down costs associated with shipping and storage, some wineries and restaurants have utilized alternative packaging, including cardboard-styled Tetra packs and kegging systems. While these approaches have obstacles to overcome in terms of brand image and the ability to control oxidation, their use is growing in the marketplace. I look forward to exploring these approaches another time.