 To have this effect, the wine is fermented twice, once in an open container to allow the carbon dioxide to escape into the air, and a second time in a sealed container, where the gas is caught and remains in the wine.Sparkling wines that gain their carbonation from the traditional method of bottle fermentation are labelled "Bottle Fermented", ""Méthode Traditionelle"", or ""Méthode Champenoise"".The latter designation was outlawed for all wines other than Champagne (which for obvious reasons does not bother to utilize it) in Europe in 1994.