Champagne is the best known sparkling wine. It comes from the Champagne region of France. While some other countries allow the use of the word Champagne for domestic sparkling wines, this practice is illegal in Europe. Using the name Champagne for other sparkling wines becomes particularly egregious when the sparkling wine in question is not even made in the Champagne Method.
There are three ways to make a wine sparkle in descending order of quality.
• Champagne and Transfer Methods
• The bubbles are produced in a bottle
• Charmat Method
• The bubbles are produced in a vat or tank
• Like soda pop the bubbles are produced by adding CO2
All sparkling wines start as finished wine. Most of the time it is made from white wine. Quite regularly the white wine is made in part or even completely from red wine grapes, the trick to getting clear juice out of black grapes is careful pressing.
There are some dark sparkling wines, these start with red wine. The lighter colored rose style of sparkling wine often has red wine added to it at the end, or in the better examples, the wine is a rose to start with.
The wine is transferred into a bottle along with yeast and some sugar (for the yeast to live off of) . The yeast do what yeast do, they eat the sugar, and expel alcohol, carbon dioxide and some heat. The carbon dioxide has no where to go in the sealed bottle, and so it mixes with the wine, making it sparkle. Eventually the yeast run out of sugar and die off. Now you have a cloudy bottle of sparkling wine with a bunch of dead yeast in it.
In the old days, and still in some smaller or higher quality brands, the process of removing the yeast was done slowly by hand. Now it is more often done more quickly and economically with a machine.
Either way, the trick is to gently coerce the yeast to end up in the neck of the bottle, and for the bottle to end up neck down. In the hands on method the wine is put into an A-frame rack in a horizontal position. A mark is made on the bottom of the bottle with chalk and over a period of time, often years, the wine is turned a few degrees and after it has gone all the way around, it is tilted slightly vertical and the turning operation is repeated.
The mechanical version of this process does it much more quickly and does not require specialized labor.
Once the yeast is all together, the neck of the bottle is plunged into a very cold brine solution (salty water). This freezes the wine around the yeast, and when the bottle is opened it expels the plug of ice and the problematic yeast with it.
The bottle is now missing a bit of wine, and so it is replaced, along with some amount of sugar. This "dosage" of sugar determines what style of sparkling wine it will be. This ranges from Brut, the driest to Extra Dry, a sweeter style (even sweeter styles exist but are not as fashionable anymore). Some producers add a bit of brandy along with the sugar and wine in the dosage, adding some extra flavor.
The process usually takes place in standard sized bottle, so larger format bottles of sparkling wine have been filled from several other bottles when the entire procedure is complete.
The finished sparkling wine is corked and sent off to be sold. Once the yeast is removed sparkling wine does not really improve with age, although some people enjoy the slightly oxidized and flatter style of aged bottles.
Fermented in bottle on the lees (dead yeast), and then the wine is transferred from bottle to a tank to be mixed with all of the other bottles, and then filtered and rebottled. A cheaper way to approximate the taste of wines made with méthode champenoise and may allow for more consistent wines.
The wine is put into a vat along with sugar and yeast to produce the bubbles. Once the yeast are finished with their job the wine is transferred into bottles, leaving the yeast behind in the tank.
This is a much easier and less costly method, but the result is usually a wine with less of the toasty flavors the yeast imparts. The bubbles too tend to be larger than the Champagne Method, and in sparkling wines, the bubbles are a main indicator of quality. Charmat method is particularly good for fresher fruitier styles of sparkling wines.
This is the industrial approach for the very least expensive styles of sparkling wine. There is no flavor from yeast and the bubbles are quite coarse. The only advantage is economic.