“Stick a Screwcap in It. . .”

That’s something winemakers may be saying a lot more of in the future, as screwcaps continue to improve, gain consumer acceptance and make in-roads versus natural cork stoppers.

The percentage of North American wineries using screwcaps on at least some of their wines has reportedly risen from five percent in 2004 to 38 percent in 2013, though natural cork still dominates the American wine market. Not so in Australia and New Zealand, however, where some 85 to 90 percent of all wines are sold with screwcap closures.

The reasons are simple. Screwcaps are cheaper and easier to open, store and ship. The big reason, though, is something called 2,4,6-Trichloroanisole or TCA, a compound that can infect natural cork and transfer itself to wine, caus-ing characteristic moldy “wet dog” aromas and flavors. It’s estimated that any-where from three to 10 percent of all wines are “corked,” costing vintners mil-lions of dollars a year and turning off consumers who found their favorite bottle of wine suddenly smelled like Fido in a rainstorm.
But there are some caveats. Natural cork has “breathability,” the capabil-ity of letting in tiny amounts of oxygen that help a wine age properly but not so much as to cause it to oxidize. Natural cork is more environmentally friendly, and is still by a large margin consumers’ preferred wine closure. And let’s face it, there’s not much romance in the sound of someone twisting off a screwcap.

Still, screwcaps’ price, ease of use and shipping, and immunity to TCA may be increasingly tough to ignore by vintners and consumers alike. Already some manufacturers are selling screwcaps that mimic cork’s breathability, and consumer acceptance is growing. The results of a study by UC Davis on the af-fects of different types of closures on 600 bottles of Sauvignon Blanc may shed more light on the subject. Or it may just keep the debate going.