Sparkling wine can be produced with one or two fermentations. The most common methods use two fermentations.
There are several methods of producing sparkling wine. The production of most sparkling wine requires two separate fermentations. During the second fermentation, a mixture of sugar and yeast are added back to the wine called a "liqueur de tirage" to initiate the second fermentation. After this step, the winemaker seals off the fermentation vessel, keeping the carbon dioxide trapped. It remains dissolved in the wine until someone opens the vessel. Then, “pop!” and bubbles ensue. The common production methods requiring a secondary fermentation are:
Traditional Method / Classic Method / Methode Champenoise
Transfer Method / Transvasage
Charmat Method / Tank Method / Cuve Close
Continuous Method
Traditional method is the term used for sparkling wine that undergoes secondary fermentation in the same bottle that goes into the vintner’s cellar and eventually onto the retailer’s shelf. It is also referred to as 'bottle fermented'. The bottle fermentation allows for optimal direct yeast contact with the wine, adding character and complexity. In Champagne, this method is referred to as "method champenoise". Some places outside of the EU label them “méthode champenoise”, but that term is not permitted in the EU for wines other than those from Champagne. Sparkling wines that are made with this method outside of the Champagne region of France may be labeled “traditional” or “classic method.” In France, the term "cremant" signifies a sparkling wine made with the traditional method and is used in areas other than Champagne. Sparkling wine produced with the traditional method in South Africa are called "cap classique."
Refer to our Champagne Production - Traditional Method webpage for an in-depth description of the traditional method.
With the transfer method (or transvasage) production is similar to the traditional method in that the secondary fermentation takes place in a bottle, but it is not the bottle that will be sold in the retail market. After the second fermentation has been completed (in a bottle), the winemaker transfers the wine from the bottle to a pressurized tank (to preserve the CO2), filters out the dead yeast and rebottles in the appropriate retail bottle. This process is used for some commercial quality sparkling wines but is also used in Champagne when bottles for retail sales are very small such as splits (187 ml) or when filled in extra large bottles larger than a Jeroboam (greater than 3 liters). Due to the small or very large bottle size, the production techniques used in the traditional method are impractical.
A third method, the “tank” or “charmat" method, is relatively inexpensive and used for bulk production of sparkling wine. This method entails secondary fermentation taking place in vats or tanks. After primary fermentation, the "liqueur de tirage" (solution with yeast and sugar) is added to the base wine to start the secondary fermentation which takes place in large, pressurized tanks. Not nearly as much direct yeast contact occurs in these large containers. As a result this type of sparkling wine may lack the complexity gained through the traditional method. When fermentation is complete, the wine is bottled under pressure. This method may not be ideal for chardonnay and pinot noir blends. This does not mean that sparkling wines produced with this method do not deserve attention. Many wines made this way, such as Italian Prosecco, are quite enjoyable and are well suited to the process that preserves the essence of the aromatic grapes.
The (Russian) continuous method is an adaptation of the tank method. It was developed in the USSR and includes a sequence of connected pressurized tanks. Base wine is pumped into the first tank. Measured amounts of the "liqueur de tirage" (solution with yeast and sugar) are added for the secondary fermentation. Then the wine passes through additional tanks containing wood shavings or chips. When the wine reaches the final tanks of the series, it is clarified and any remaining sediment removed. At the end of the process, the wine is bottled.
In addition to the methods requiring secondary fermentation, there are two methods of sparkling wine production that only require one primary fermentation. They are:
Méthode Ancestrale / Méthode Rurale
Carbonation
The méthode ancestrale or rurale was the predecessor of the traditional method. With the méthode ancestrale, the wine is bottled prior to completion of the primary fermentation. No additional sugar and yeast are added and he fermentation that occurs in the bottle is essentially a continuation of the primary fermentation. Even though the method is considered primarily historical, there are a few areas in France that continue to produce sparkling wine in this way.
The final and most inexpensive method for producing sparkling wine involves simply injecting CO2 into the wine, with no secondary fermentation occurring. The process is much like that for colas and sodas.
Sparkling wines are not always labeled so consumers can immediately tell which process was used. Usually wines made using the Traditional Method will be labeled as such. Wines from France that are labeled champagne or cremant are always made using the traditional method. Wines made using the Transfer Method may state 'fermented in a bottle', which implies they were transferred to the retail bottle after the secondary fermentation. Charmat and CO2 infused wines usually have no indication of method on the label. If you can't make the determination and are curious, you can ask the winemaker. Sometimes it is good to form your own opinion with a blind tasting.