Champagne guru Chris Sheehy has put a cork in the myth that a spoon in the neck of a champagne (or sparkling wine) bottle keeps it fresh.

“Truthfully, the teaspoon has zero effect,” the prestige manager for Pernod Ricard Australia told news.com.au writer Andrew Bucklow.

“The theory is that you put a cold spoon into the neck and that makes the air around the spoon colder, so more dense. Because it’s denser, the bubbles won’t escape past it, so it’s almost like an air blanket that sits on top of the bottle so that the CO 2 stays inside the bottle.”

“We’ve looked at different ways and methods to keep champagne fresh and the old spoon in the bottle trick always comes up the same as if you just leave the bottle in the fridge with nothing in it at all,” he said.

So, how do you keep your leftover champagne fresh?

“If you do have some left, the most important thing is the temperature,” Mr Sheehy told news.com.au. “You should never let the bottle warm up and then chill it down again. If you can keep it cold at all times, that will hold the bubbles/carbon dioxide in the liquid.

“The next factor would be how much Mumm champagne is left in the bottle,” he continued. “If you’ve only had one glass from the bottle then there’s not much oxygen within the bottle itself, so it will tend to last longer. But if you’ve only got a small amount left, like one glass in the bottle, it will have been losing its fizz far quicker no matter what you do.

“The rule of thumb for me is if you’ve got one glass left in the bottle then don’t even try and save it, just enjoy it.

“The next factor is the closure system,” Mr Sheehy said. “If you do have a champagne stopper, they’re relatively easy to find and pretty cheap, keep the bottle nice and cold the whole way through and put the stopper in if you’ve got at least half a bottle or more left and get it back in the fridge.”

He went on to say that if you keep the bottle cold, have more than half the bottle left and use a stopper, the champagne should stay fresh for another 24 hours, but less than half a bottle will deteriorate after just four or five hours in the fridge.