What are Sparkling wines and how are they made?

What is Sparkling Wine?

Sparkling wine is any wine that is carbonated, which includes Champagne.  It can be made from red and white grapes, either as a single grape varietal or as part of a blend - such as the famous Champagne blend of Pinot Noir, Pinot Meunier, and Chardonnay.  Sparkling wines are most commonly white, but they also can be rosé.  There are even some red sparkling wines such as Italian Lambrusco.  There are over twenty different types of sparkling wine that are made in both the Old and New World. The production of sparkling wine can be a very labor-intensive process depending on which winemaking method is used and this is therefore reflected in the final cost of the wine.  The good news is that if you do not want to pay the higher price that Champagne often commands, there are many reasonably priced alternatives out there that are excellent. Though associated with celebration, a glass of sparkling wine can be enjoyed whenever you wish.  It pairs well with most food and is perfect on its own.

How is the Sweetness level measured in Sparkling Wines?

The grams of sugar (added per liter) are used to measure the sweetness of sparkling wines.  This is calculated using the Champagne sweetness scale.

  • Brut Nature - 0-3g 
  • Extra Brut - 0-6g
  • Brut - less than 12g 
  • Extra Sec - 12-17g 
  • Sec - 17-32g 
  • Demi-Sec - 32-50g
  • Doux - 50g or more

How are the bubbles formed in Sparkling Wines?

The bubbles in sparkling wine are created by the build-up of carbon dioxide which occurs during the second fermentation (or by injection if the Carbonation method is employed).  The bubbles cannot be seen in a sealed bottle of sparkling wine.  They only become visible at the time that the cork is removed from the bottle which releases the pressure in the bottle as the carbon dioxide escapes.  If the cork is removed too quickly from the bottle, there will be an overflow of foam.  The bubbles that rise to the surface of a wine glass occur when the wine comes into contact with any residual dirt or dust particles in the glass. This is natural and there are no health risks.

The Méthode Champenoise

Champagne can only be produced in Champagne France and must be made by using the Méthode Champenoise:  

  • Harvest - Grapes must be harvested between August and October, and picked when they are at optimal ripeness.  As a general rule, the grapes must be hand-picked, ensuring that only the best fruit is transformed into Champagne.  
  • First fermentation - After the grapes have been pressed, the juice is moved to a tank (or in some rare cases, an oak barrel) where a dry still wine is produced.  The winemaker also ensures that the natural sugars ferment completely out of the wine.
  • Assemblage - The still wine is mixed with reserve wines (these wines have been kept from former harvests so that they can be used for blending).  This usually takes place after the wine has fermented for around five months.  This process only occurs for Non-Vintage and Multi-Vintage Wines which are the base for the Champagne. The grape varieties are blended after the reserve wine has been added which then creates the final blend.  No reserve wines are added to vintage wines as the wine must only contain wine that is from the current harvest.
  • Second Fermentation - Once the first fermentation is complete a Liqueur de Tirage (A mixture of sugar, yeast, and yeast nutrients) is added to the still wine which is then transferred into thick glass bottles and sealed with a special crown cap (similar to the cap on a bottle of beer).  The filled bottles continue their slow fermentation process in a cool cellar, producing carbon dioxide and alcohol. 
  • Aging -  The fermentation process continues and carbon dioxide begins to build up in the bottle causing the yeast cells to slowly die. The dead yeast cells eventually split apart mixing into the wine giving Champagne its characteristic yeasty flavor.  This aging process is called sur lie (on lees).  The minimum aging period for Non-Vintage Champagne is fifteen months and three years for Vintage Champagnes, though many of the elite Champagnes (both vintage and non-vintage) age their wines for five years or more.
  • Riddling - The bottles are placed upside down into a machine (Gyropalette) at a 75° angle once the yeasts are dead.  Every day until the wine is disgorged, the Gyropalette rotates each bottle 1:8th of a turn, which gently draws all of the dead yeast cells downward into the bottleneck.  Before the invention of the Gyropalette the bottles were all turned by hand, a skilled remueur (bottler turner) could rotate up to 40,000 bottles in a single day!
  • Disgorgement - The final step of the Champagne production process is when the upside-down bottlenecks are plunged into a bath of ice salt, freezing the dead yeast cells into a plug that is forced out when the crown cap is removed by the carbon dioxide that has accumulated in the bottle.  This process results in a tiny loss of wine, but the remaining liquid is cleared of any imperfections.
  • Dosage - Once disgorged, the missing wine in the bottles is topped up with Liqueur de Tirage and Liqueur d’expédition (a combination of white wine, brandy, and sugar). This dosage will determine the final sweetness category of the Champagne.
  • Corking -  Once the bottles are filled, they are then sealed with a special Champagne cork and then secured with a Muselet (tiny wire cage) that keeps the cork secure under the high level of pressure (typically around 6-8 bars) that is created by the build-up of carbon dioxide in the bottle.  Once the corking process is completed, the Champagne is either released immediately onto the market or kept in the cellar for further aging.

Sparkling Wine Production Methods Around the World

Worldwide, there are four different methods of production are used to make non-champagne wines.

  • Méthode Traditionelle - is similar to the Méthode Champenoise (minus the strict production rules) and may be used for any non-Champagne sparkling wine. Only Champagne may use the Méthode Champenoise.
  • Charmat or Tank Method - The still wine is transferred to a pressure-sealed tank once the first fermentation is complete.  The second fermentation is caused by the creation of carbon dioxide.  Once the second fermentation is complete, the wine is bottled for immediate release to the market.
  • Transfer Method - A combination of the Traditional and Charmat methods, the second fermentation takes place in the bottle.  The sparkling wine is then transferred to a tank for filtration - an economical way of producing sparkling wine as it removes the need for riddling and disgorgement. 
  • Carbonation - this is the cheapest method that can be used to make sparkling wine. Carbon dioxide is injected into the wine once the first fermentation is complete.  The wine is then bottled under pressure and released to the market for distribution.

Prosecco from Italy and Champagne from France are the most popular sparkling wines in the world.  Champagne, (the most luxurious form of sparkling wine) has been made since the late 1600s gaining immense popularity since its creation.  Prosecco, (the world's most popular sparkling wine) on the other hand has been around since the 1700s but has only gained worldwide popularity in the 21st century as a good quality much cheaper alternative to Champagne.

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