The question often comes up : these small bubbles in the Champagne flute, is it there because gas is added or injected into a « still » wine ? Although this unorthodox « treatment » that could be called « Coca-Cola method » is practiced for some sparkling wines , the genuine beautiful bubbles actually come from a method a bit more complex and all-natural.
Whether it is for Champagne, Spanish Cava, Prosecco or others, here is how this sparkling wines production works. Follow the guide!
The most famous sparkling wine is Champagne and certainly that’s good because its method of production is definitely the benchmark in the field. By the way, only Champagnes can wear this name if they were designed in the territory of the appellation of Champagne, in the region of Reims and Epernay in north-eastern France, neither more nor less.
1) Méthode champenoise
Once the freshly picked grapes are sorted and pressed, the must (or juice if you prefer) will be put into vats for 2 weeks during which the magic of fermentation will operate. This means that sugar content in the grapes will turn into alcohol, thanks to the natural yeast present in the juice. During this fermentation, carbon dioxide will appear, but this is not the gas that will make the wine sparkling.
Second fermentation in the bottle
The winemaker then decide to assemble (blend) the different grapes he wants to use for his wine. In the case of Champagne, he can assemble the Pinot noir, the Pinot meunier and Chardonnay for example. (Note: Even with two red varieties and one white, the wine is still white, since rather the short maceration will not give the red color to the final product). When finished blending, the wine is then bottled after adding sugar and yeast. The winemaker will then close the bottle with a cap (similar as the ones for the beer) rather than a cork. Because that’s where the « still » will become a sparkling wine. But that’s not all…
After a period of 15 to 36 months, during which the bottles are stored in the cellar, the producer will proceed to « riddling » or « remuage ». In fact, it means that he will rotate the bottle from left to right and put it upside down so that the organic deposits (yeast and other sediments) build up will sit towards the neck of the bottle.
Goodbye cap, hello cork !
Most of the time, the neck of the bottle is then immersed in a liquid at minus 25 degrees Celsius so that these unwanted deposits are frozen. Then simply the winemaker will uncap the bottle to expel the « icicle » imprisoning yeasts and deposit (dégorgement). Since a part of the liquid has been removed, the winemaker will then replace this « lack » of liquid with some wine and sugar. That’s what is called the « liqueur de dosage ». It is this mixture that will determine whether the sparkling wine is dry (brut, extra brut), off-dry or sweet (sweetest).
Finally, the bottle is closed with a cork (mushroom-shaped), surmounted by a cap and wire cage (muselet). Everything will then be « dressed » with the label and the flange (collerette). This production method called champagne or traditional method is the same, pretty much, used to produce the Spanish sparkling wines called cavas. This results in sparkling wines generally more complex than for other manufacturing methods.
2) Method of the closed tank
To produce other sparkling wines that are fruitier, we will choose the method of the closed tank (cuve close) or Charmat method. This is the case for good Prosecco (sparkling wine from Veneto in the Northern Italy), the Sekts (from Germany) or the Italian Piedmont Asti.
The beginning of the preparation is similar to that of the champagne method. Except that the secondary fermentation is not done in bottles but in a pressure vessel. And since a part of the CO2 escapes during the bottling, some carbon dioxide will be added to compensate. The wines made with this method are generally fresh and fruity.
3) Tranfer method
Finally, another popular method especially in New Zealand and Australia is characterized by a concept less complicated, less expensive and therefore is not to disgorge the bottle. The sparkling wine is already removed from the bottle (the bottles are rinsed for reuse), the wine is filtered in a pressure vessel in which they will add the liqueur de dosage. The wine will then be directly bottled with natural carbon dioxide.