Each reusable 5-gallon stainless-steel barrel holds the equivalent of 25 bottles of wine (15.5-gallon kegs also are available). The contents are kept pressurized by argon, a nontoxic gas that is naturally present in air. The result is 125 glasses of wine, the last tasting as fresh as the first.There are many virtues to this practice. When restaurants serve wine by the glass, they regularly have to dump half-bottles that have been sitting too long. Packaging in bulk keeps prices lower, so customers can find expensive wine for a relative bargain if it comes from a keg. And kegs are also really good for the environment.
"What's really great is, because of the lower cost of production, we can sell what would normally be a $20 glass of wine for $7 or $8," says Sean Culley, general manager at [Portland's] The Melting Pot.... "The other thing is the sustainability factor. They don't have to use and ship the bottles, labels and corks, and we don't have to throw them away," says Culley.(In the entertaining photo I found on the winery's Facebook page, you can see just how sustainable kegs are--note the Elysian keg in the foreground.)
I don't know how many wineries in the US current do this--maybe Woolridge Creek is the first--but it certainly seems appropriate for Oregon wine to be served in kegs. Maybe wineries and breweries can start bartering--stainless steel kegs for used pinot casks.