Is it time to amend the warning label on each bottle of wine sold in the United States? Two developments that surfaced at the current Unified Wine & Grape Symposium in and about the Sacramento Convention Center suggest it is:

- One topic irritating the country's wine-grape growers is the use of the appellation "American" on wines that might include a hefty portion of juice from Australia, France or some other country. Under current law, a wine with an "American" appellation can include up to 25 percent juice from vineyards outside the United States. Opinion at the conference was divided over whether this practice is increasing or remaining steady, but enough farmers are concerned about the issue that the California Association of Winegrape Growers is exploring possible ways to assure that American wines are American, said Rodney Schatz, the trade group's chairman.

For one, the organization may ask federal authorities to amend the regulation that allows foreign juice to be blended into American wines. Another option is to appeal to California legislators to adopt a measure stipulating that any wine bearing the "California" appellation be made entirely with California fruit. Longtime wine-industry consultant Jon Fredrikson said the American appellation was adopted in the 1970s when California wines were being blended with New York wines to help compensate for a shortage of Empire State grape juice. If lawmakers don't come up with a solution along one of the lines suggested by Schatz, maybe they can agree to tweak the existing warning label on bottles of wine to read: "This American wine may not be entirely American."

- And while they're at it, perhaps they can add this line: "Before applying corkscrew to cork, make sure the cork is cork." This thought came to mind after stopping by the booth of Alcoa Vino-Seal, one of scores of exhibitors trying to entice symposium attendees into buying everything from oak barrels to a robotic vine pruner. At Vino-Seal, Justin Davis was talking up a new kind of bottle cork that is made of glass. Rip off the foil on the neck of the bottle and what you find is a short, solid cap of clear glass. Just grab the edge of the cap and pull. No special equipment needed. Davis, Vino-Seal's product manager, is promoting the cap as a convenient and elegant alternative to both traditional cork and screwtops. Corks often are unreliable in guaranteeing the soundness of a wine, while some consumers are hesitant to embrace screwtops because they seem more utilitarian than glamorous. Glass avoids both issues, says Davis. The stoppers are made in Germany, where they were introduced in 2003. Whitehall Lane Winery in the Napa Valley is the first producer in the United States to take advantage of the stoppers, for 8,000 cases of its reserve cabernet sauvignon, Davis says. More California wineries are showing interest in the glass caps, and he's predicting 100,000 cases will be topped with the closures this year. He expects wineries to warn consumers of the surprise awaiting them under the foil with either neck hangers - an approach taken by Whitehall Lane - or a statement on the back label.