Wednesday, June 13, 2012

Champagne: The traditional method

Champagne is one of the world's most celebrated wines, the beverage that is, almost universally, tied to adult rite-of-passage events.  The production of Champagne is among the most complex wine production processes and the quality of the product is a testament to the art of blending as practiced by the Chefs de Cave of the prominent Champagne Houses.  This post covers the traditional method for the production of Champagne.  While this method is utilized in the construction of many of the world's sparkling wines, they lack one of the key Champagne critical success factors; grapes grown on the soil of the Champagne region.


The first "blending" decision that is made by a Champagne House is the mix of grapes that will be included in the cuvée or vintage for a specific year.  In my recent post on the terroir and viticulture of Champagne, I pointed out that the Houses only own 10% of all grapes grown in the region.  They have access, however,  to fruit from a broad range of cru vineyards in the major districts and the decision as to which variety to acquire from which cru in which district will have an impact on the style of wine that is produced by that House in that season.


The steps associated with the traditional method follow.

Picking

The starting date for picking the grapes is set by the CIVC (the organization that "coordinates the common interests of wine growers and producers in Champagne") which bases its decision on input from the ripening observation network which was initially established in 1956.  This network allows input variables from 450 control plots to be analyzed and the grapes tracked for ripeness by cru and variety.  Decisions on picking dates, quantities, and alcohol levels are a direct result of this analysis.

Over 100,000 pickers are involved in harvesting the ripe grapes and moving them from the field to one of the 1900 pressing stations that are located throughout the region.  The grapes are picked in clusters and then placed gently into waiting plastic bins.  Picking normally begins in the cool of dawn in order to preserve as much of the grapes' freshness as possible.  Chardonnay is generally picked one or two weeks later than Pinot Noir and Pinot Meunier.

Pressing

The grapes are weighed at the pressing center and relevant information recorded in the pressing logbook.  The grapes are then pressed as whole bunches in a process that is called fractionated winemaking.  In this process, the free-run juice is drawn-off first in three successive pressings.  The product of these pressings is called the cuvée and the middle of the three is called the coeur de  cuvée (heart of the cuvee) and is said to possess an ideal balance of purity and structure.  The maximum amount of juice that can be harvested during the cuvée pressing is 20.5 hl.

The second component of this fractionated winemaking is the heavier press called the taille.  In this stage the juice is harvested in two or three high-force presses that occur subsequent to the removal of the cuvée.  The juice collected at this point is darker due to the impurities extracted from the grape skins.  A total of 5 hl of juice can be legally harvested at this stage.

The cuvée and taille have similar levels of sugar but the cuvée has higher levels of malic and tartaric acids while the taille has higher levels of oxidants, minerals, and pigments.  A total of 25.5 hl of juice can be legally harvested from a 4000 kg marc of fruit.

Addition of Sulphites

The fruit extracted during the press flows into open tanks which are separated by cru, variety, and pressing (If the intent is to make Rosé Champagne via maceration, then the juice stays in contact with destemmed black-skinned grapes  for 24 to 72 hours until the desired color is obtained.).  Sulphites are added to the juice at between 6 and 10 g/hl in order to combat mold and bacteria and reduce the risk of flavor-killing oxidation.

First Racking (Débourbage)

Impurities are removed from the juice through a process called débourbage where the solids fall to the bottom of the tanks while the clear juice is drawn off from the top.

Alcoholic Fermentation

The resulting clear juice is transported to the vat room for alcoholic fermentation.  Today most fermentation is carried out in stainless steel tanks, a change from the prior norm of oak fermentation  (Oak seems to be making a comeback and I will cover its use in Champagne in a future post.).  The juice is chaptalized as necessary to bring it up to 11% potential alcohol after which yeast is added to initiate alcoholic fermentation. Fermentation runs between 10 and 14 days before all the sugar in solution is converted to alcohol and carbon dioxide.  The carbon dioxide produced at this phase is allowed to escape.

Malolactic fermentation is initiated if is a part of the house style.


Cold Stabilization and Clarification

The base wine is cold stabilized to prevent tartrate precipitation later in the life of the wine.  The wine is then racked off the solids and clarified further through fining and/or filtering.

Blending

The next step in the process sets Champagne apart from other sparkling wines and sets the Champagne Houses apart from Grower-Producers.  In order to produce Champagne that aligns with the House style, the Chef de Cave has to memorize and blend wines from a broad array of crus from the current vintage plus wines from the reserve as necessary.  The Grower, on the other hand, is working with a smaller geographic area and a far smaller number of vintages as the base wines for his/her blend.  In the case of a vintage Champagne, the blend can only contain wines sourced from grapes that have been harvested and fermented in the vintage year.

In-Bottle Fermentation

The blended wines are placed into Champagne bottles to which liqueur de tirage (a solution of wine, sugar, and yeast) is added and then the bottle is capped with a crown cork seal.  This addition precipitates a second fermentation, this time in the bottle.  As the bottle is capped, the carbon dioxide created during fermentation cannot escape and the bubbles formed as a result is absorbed into the liquid.  The process by which these bubbles are formed is called prise de mousse and the longer the period, the more refined the bubbles.

Aging

After the sugar has been exhausted, the yeasts die.  The breakdown of the dead yeast cells by enzymes -- autolysis -- adds complexity to the aroma, flavors, and mouthfeel of the Champagne if residency is maintained.  Champagne is legally required to remain on the lees for > 16 months if a non-vintage and > 3 years if designated as vintage.  Quality houses normally age their non-vintage wines for 3 to 4 years and their vintage wines for 7 to 8.

Remuage and Disgorgement

When the house deems that the Champagne has spent enough time on the lees, steps are taken to remove said lees from the bottle.  This is a two-step process with the first step (remuage) designed to move the sediment from the body of the bottle and into the neck and the second step (dégorgement) designed to expel the sediment from the bottle.  In the first step, the bottle is moved slowly from a  horizontal to a vertical, neck-down position, while simultaneously turning it a few degrees at a time to dislodge the sediment from the walls.  This process had historically been done by hand but is now done by a machine (gyropalette) which has resulted in a dramatic reduction in transit time and a marked increase in throughput volume.  Large format bottles are stilled "riddled" by hand.


In the disgorgement phase the bottle is passed neck-down through a freezing brine solution which causes the freezing of the sediment-containing liquid in the neck of the bottle.  Removal of the crown cork seal will cause the pressure in the bottle (6 atmospheres) to forcefully expel the frozen material from the neck.

Liqueur de Dosage

A mixture of base wine and sugar (liqueur de dosage) is added to the Champagne bottle in order to top it up and to attain the desired sweetness level, measured in g/l:

  • Zero dosage -- 0 to < 3 g/l
  • Extra brut -- 3 to < 6 g/l
  • Brut -- 6 to < 12 g/l
  • Extra dry -- 12 to 17 g/l
  • Sec -- 17 to 32 g/l
  • Demi-sec -- 32 - 50 g/l
  • Doux -- > 50 g/l
The bottle is plugged with a standard Champagne cork and a steel cage placed around the neck and over the cork to hold it in place.  The bottle is shaken vigorously and left to sit for 6 months to ensure full integration of the liqueur de dosage into the wine.

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The above described method produced 322 million bottles in 2011of which 69% (222 million bottles) were produced by the Champagne Houses with the remaining 31% produced by Growers.  Fifty-six percent of the Champagne produced was consumed in France with the remainder being shipped abroad to the United Kingdom, United States, and Germany among others.  This export market is dominated by the Champagne Houses as only 13% of Grower Champagne is exported.  The Champagne House-Grower split is more evenly balanced within France with 55% of consumption being sourced from the Champagne Houses.

© Wine -- Mise en abyme

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