If you had trouble polishing off any open bottles of sparkling wine on New Year’s Eve, you may have employed an old kitchen trick to keep the leftover bubbly ... well, bubbly.

The trick is simple: just put a teaspoon, handle down, into the bottle’s mouth. Many people have cited anecdotal evidence that the spoon helps keep sparkling wines effervescent in the fridge for a day or more after opening.

There’s just one problem. Belief in the spoon tactic, which is of uncertain origin but seems especially prevalent in Europe, appears to be misplaced.

“I think it’s a myth,” says Stanford University chemist Richard Zare, who undertook an extracurricular investigation of the teaspoon’s preservative powers in 1994. Zare, along with food writer and San Francisco Bay Area resident Harold McGee, their wives and other friends, uncorked several bottles of bubbly and refrigerated them for 26 hours under different preservation methods—including some with spoons and some without. Then they sampled and scored the sparkling wines in a blind test. The result: Zare and his fellow testers did not detect any boost in the sparkle of the spooned bottles. A more recent, smaller-scale test on the television show MythBusters arrived at a similar conclusion.

Although Zare's study was somewhat informal, he believes the methodology was solid. “Hal McGee had just bought a new refrigerator that had nothing in it,” he recalls. “This was great—because it had no smells or anything in it.” And the bottles of wine, which all came from the same lot, were kept under identical ambient conditions. “We really tested it quite extensively,” Zare says.

What is more, the California test jibes with the results of a similar experiment conducted around the same time by researchers at the Interprofessional Committee of Champagne. The CIVC, as it is known by its French initials, is an association of grape-growers and winemakers in the Champagne region of France that defends the literal geographic meaning of the appellation “champagne”—bubbly from other locations is sparkling wine. “The experiment was done in pernay, near Reims, with champagne from the same batch, and the pressure was measured in various circumstances, such as opened bottles, opened bottles with spoon, bottle closed with stopper [and] bottle closed with cork (after having been opened),” wrote chemist and food journalist Herv This in an e-mail; This described the research in his 2006 book, Molecular Gastronomy. “The pressure in bottles opened and left open or in bottles opened and left open with a spoon decreased in the same way—whereas a stopper or cork prevented the gas escape,” he added.

So if the dangling teaspoon appears to have little to no effect on preserving carbonation, what is a champagne sipper to do with his or her half-empty bottle? No special stopper is needed, says Zare, in whose (admittedly subjective) taste test recorked wine rated poorly. “Keep it cold. In fact, never let it warm up. That’s the secret,” he says. The reason: in many liquids, including water, carbon dioxide is more soluble at low temperature, so cold liquids better retain their dissolved gas. Some sparkling wines are so saturated with carbon dioxide, Zare says, that they can remain bubbly in the fridge for days, even without a stopper. “If you keep it cold from the start,” he adds, “it just goes on and on.”