Production of Sparkling Wine
During fermentation the sugar converts into alcohol and carbon dioxide as by product. If this carbon dioxide is trapped within the wine, the end result is a sparkling wine. A cheaper option, but never used in quality sparkling wine, is to induce carbon dioxide into the bottle at the time of bottling. In all fine sparkling wines the carbon dioxide is put into the wine by subjecting it to a second fermentation.
The most famous of sparkling wine is Champagne from the Champagne district of France. In fact it is so famous that sometimes the world champagne is used generically for all sparkling wines that have been made by the traditional method or methode champanoise. However, only sparkling wine originating from champagne district of France can be legally called champagne.
- Pressing: The grapes are pressed to extract the juice. The juice obtained from the first pressing is known as cuvee and the one obtained by subsequent pressing is called taille. Only cuvee is used to make sparkling wine.
- The first fermentation is carried out as for any other white wine. The fermented must is clarified by cold stabilization, centrifuge and/or by filtering.
- Blending: Wines from different vats and from older years is blended to produce wine that is consistent with the house style.
- Second Fermentation: A blend of wine sugar and yeast known as liqueur de triage is added to wine before bottling to stimulate second fermentation, which takes place inside tightly sealed thick glass bottles stored horizontally.
- Aging: The wine is allowed to age in the bottle for minimum of two year (some times 20 years or more). This is called aging on lees.
- Remuage (Riddling): After fermentation and aging the dead yeast cells get stuck to the sides. The bottles are rotated and tilted downwards till upside down, so that all the sediments comprising of yeast cells gets accumulated at the neck of the bottle.
- Disgorging: The neck of the bottle is passed through a solution that freezes the sediments into solid plug. As the cap is removed the pressure of the gas from the champagne forces the plug out.
- Dosage: Each bottle than topped up with liqueur d’expeditions, a blend of wine and sugar in varying proportions. This process is known as dosage and the determines weather the champagne will be brut (completely dry), sec, demi-sec or doux (Sweet)
- In the end the bottle is corked and wired and rested fro three months before finally releasing it for market.
Transfer Method: This process follows champagne method till disgorging, when the wine is transferred into pressurized tanks, filtered to remove sediments and then rebottled.
Charmet Process: A tank based system; the wine sugar and yeast are place in large sealed vats for secondary fermentation to take place. The wine is chilled, filtered and transferred under pressure to a second tank, sweetened with liqueur d’expeditions and bottle. This process is also known as cuvee close