How Sparkling Wine is Made
There are three methods that may be used to make sparkling wine. These methods are:
- the Transfer Method,
- Charmat Bulk process and
- Methode Champenoise.
Now lets take a look at the three different methods vintners may use to make sparkling wines. Methode Champenoise is a more labor-intensive and expensive method than the other two methods of producing sparkling wine. After harvesting the fruit, the juice is pressed and put into containers for the first fermentation. These containers are either stainless steel vats or oak barrels. When the first fermentation is complete, various lots of wine are blended together to produce an assemblage (the final blend of varieties for the finished wine). Then a mixture of yeast and sugar, called a triage, is added to the base wine. The wine is bottled with a small plastic cup that fits in the neck of the bottle and collects any sediment. This small plastic cup is called a "bidule" The second fermentation takes place in the bottle and due to the sugar and yeast being added, alcohol and carbon dioxide are produced. Due to carbon dioxide formation and pressures up to 90 pounds per square inch, bottles for Champagne and sparkling wine must be thicker than regular wine bottles. During the second fermentation, temperature plays an important role. Cooler temperatures produce finer bubbles. Once the second fermentation is complete, dead yeast cells begin to break down and form a sediment in the wine. This process is called autolysis. The winemaker decides how long to allow for the autolysis process and this in turn has an impact on the final taste of the wine. The sediment must then be removed without losing the carbon dioxide and sparkle. The first step in doing this is riddling or remuage. In years past, this was done by inserting the neck of the wine bottle into a rack, called a pupitres, that would hold it at a 45 degree angle so the dead yeast cells would settle into the neck where the bidule was attached. Then every few days, a trained person, called a remuer, would give each of the bottles a quick shake and increase the angle of the bottles until they were eventually positioned completely downward, thereby collecting all the sediment in the neck. Today, the riddling process is automated. Next the sediment is removed by disgorgement. This is where the bottle is placed neck down in an icy brine to freeze the sediment into a solid plug. The cap is then removed and the pressure inside the bottle causes the frozen sediment to be expelled. Then a "dosage" is added. This dosage is a small amount of wine mixed with sugar and sometime brandy and it determines the sweetness or dryness of the sparkling wine. The bottle is then corked and secured with a wire hood.
The Transfer Method of making sparkling wine is similar to the Methode Champenoise except that instead of riddling to remove the sediment, the wine is transferred to a pressurized tank where the sediment is filtered. It is then bottled, corked and secured with a wire hood in preparation for sale to the public.
The Charmat Bulk Process is the quickest and least expensive method of making sparkling wine. With this process, instead of the wine going through the second fermentation in the bottle, the base wine is placed in a temperature-controlled, pressurized tank to which sugar and yeast is added. The secondary fermentation takes place in this tank without the release of any carbon dioxide. This tank acts like a very large bottle. Once the fermenting is complete, the wine is filtered under counter pressure and bottled using a counter-pressure filler. Because the wine has not spent the same amount of time in contact with the carbon dioxide, the bubbles tend to be larger and dissipate more quickly.