Sparkling wine production is the method of winemaking used to produce sparkling wine. The oldest known production of sparkling wine took place in 1531 with the ancestral method. Pressure and terminology In popular parlance and also in the title of this article the term sparkling is used for all wines that produce bubbles at the surface after opening. Under EU law the term sparkling has a special meaning that does not include all wines that produce bubbles. For this reason the terms fizzy and effervescent are sometimes used to include all bubbly wines. The following terms are increasingly used to designate different bottle pressures: Beady is a wine with less than of pressure. Semi-sparkling is a wine with of pressure. Semi-sparkling wines include wines labelled as Frizzante, Spritzig, Pétillant and Pearl. Sparkling is a wine with above of pressure. This is the only wine that can be labelled as sparkling under EU law. Sparkling wines include wines labelled as Champagne, Cava, Mousseux, Crémant, Espumoso, Sekt and Spumante. Production methods Fermentation of sugar into alcohol during winemaking always means that carbon dioxide is released. Carbon dioxide has the property of being very soluble in water (the main constituent of wine), a property that is utilized in sparkling wines. Production always starts from a base wine (where the carbon dioxide from the first fermentation has been gasified). In Champagne production, the base wine is usually a blend of wines from different grape varieties and different wineries, where the distribution gives the final wine its special character, called cuvée. In some commonly used methods the base wine undergoes a secondary fermentation, which encloses the resulting carbon dioxide under excess pressure and binds it to the liquid in the sparkling wine. In this way the carbon dioxide content is created which, after opening the bottle, produces the bubbles. The dead yeast cells form a precipitate called lees, that often help with appealing aromas to the sparkling wine but looks unappetizing. The lees are therefore normally removed before the wine is distributed. The main methods used to make sparkling wines are often given as seven, with some variations. What or which production methods that give the best wines is not a moot point, but there is some consensus that the first four methods, where the second fermentation occurs in the bottle, are usually preferable to the latter three. The following table shows the main features