(NPR) - Step aside, cork.

If you're a wine drinker, you've probably noticed that screw caps are no longer considered the closure just for cheap vino. Increasingly, bottles of very good wines are unscrewed, rather than uncorked.

Screw caps for wine bottles have been around since the late 1950s, but they were initially associated with value-oriented jugs of wine. That image started to change about a decade ago, when commercial winemakers in New Zealand and Australia started using the enclosures much more widely for all kinds of wine, including some higher-end bottles.

And according to screw cap enthusiasts, the science establishing the ability of screw caps to seal and perform well goes back to the 1980s.

So, what's the rule of thumb when it comes to winemakers choosing screw caps in lieu of corks?

Increasingly, winemakers "prefer screw caps for white wines and reds meant to be drunk young," says Dave McIntyre, a wine writer whose columns appear in The Washington Post.

Take, for instance, the wines from Cupcake Vineyards in Livermore, Calif. James Foster, the senior winemaker at Cupcake, says he loves screw caps for his sauvignon blanc and pinot grigio.

"The screw cap keeps it [the bottle] sealed and does not allow oxygen to enter the bottle," Foster says. And that, he explains, ensures that the wine remains crisp and well-preserved.