Is there a Champagne grape?
Not as such, the primary grapes used in Champagne are Pinot Noir, Chardonnay and Pinot Meunier.
Burgundy and Champagne share the same grapes, Chardonnay and Pinot Noir, though a third grape, Pinot Meunier, is also important in Champagne. A rustic, early-ripening cousin to Pinot Noir, Pinot Meunier is important because it rounds the wine out. Champagne may be one of those grapes, or a blend of two or three. (Chardonnay, Pinot Noir and Pinot Meunier account for 98% of all Champagnes produced, though a few other grapes may be legally grown and there are a few Champagne producers who use them (most famously Aubry). The Montagne de Reims is best known for Pinot Noir, the Vallée de la Marne is home to great Pinot Noir and Pinot Meunier and the Côte des Blancs produces great Chardonnay.
Where do the bubbles come from?
All wine is made a through simple fermentation process that converts sugar into alcohol. In Champagne, there is a secondary fermentation in the bottle, thanks to an addition of sugar and yeast. As this second fermentation takes place, bubbles of carbon dioxide begin to form. When this is complete, the Champagne bottle is gradually turned upside down until the yeast has collected on the crown capping the bottle. This tedious process, called riddling, was once done by hand but is now (mostly) accomplished by a machine. After as short a period as 18 months (the legal minimum for non-vintage Champagne) or three years (the vintage minimum), or as long as 10 years, the bottle is "disgorged": The cap is removed; the yeast is forced out; the wine is topped off with a small "dosage" of wine and sugar (the higher the sugar level, the sweeter the resulting Champagne) and the bottle is finally corked. The bottle remains in the cellar for a few months or years before it is shipped. A vintage Champagne is a wine from a single, presumably superior year—and comes with a higher price tag.
While the first Champagnes were very sweet, Champagne has grown much drier over the years, and the average "dosages" are getting smaller. Some producers now aren't adding dosages at all: These wines may be designated as Non Dosage or Brut Zero. Moving along the spectrum in order of ascending sweetness, you'll find Extra Brut, Brut (the most common designation), Extra Dry, Dry, Demi-Sec and Doux.
There are also several Champagne colors: Blanc de Blancs (all Chardonnay) Blanc de Noirs (a white wine made from red grapes) and rosé, which is produced either by blending red and white wine or by the saignée method, which allows a brief contact with the skins of red grapes.
Unlike in Burgundy, where vineyards are ranked, or Bordeaux, where wine estates are divided into classifications, in Champagne the classification system is based on the villages where the vineyards are located. There are 319 villages in Champagne and 17 that are rated "grand cru" in recognition of the quality of their terroir. Another 43 are designated "premier cru," just below grand cru. The rest are unrated, even if some might (and do) produce exceptional wine. Growers in grand cru villages get the highest prices for their grapes from Champagne houses, those in premier cru villages get about 90% to 99% of those figures and those in unrated villages may get as little as 80%.
This system called the" echelle des crus," - the ladder of growth, was implemented about 50 years ago to protect Champagne growers. Champagne houses had once sourced outside the region for grapes, a practice that has long been outlawed. There is a delicate balance between the Champagne houses and the growers, who own the vast majority of vineyards but produce very little wine. Instead, most growers sell their grapes to the big Champagne houses, whose wines are designated "NM" (négociant manipulant) on the label. There has been an increase in the number of growers making their own Champagnes in the past couple of generations—their wines can be identified by the letters RM (récoltant manipulant).
If you're drinking Champagne this coming festive season, the odds are great that it's non-vintage—a blend of several vintages, from dozens to even hundreds of wines from different harvests, styled to taste the same year after year. Non-vintage Champagne accounts for the majority of production for most Champagne houses. For example, at Louis Roederer, the home of Cristal, the Brut Non-vintage accounts for 75% to 80% of total production. The term "non-vintage" has fallen out of fashion with some producers, who prefer the more positive-sounding "multi-vintage," though I've yet to hear someone ask for a "multivintage" Champagne in a restaurant or retail store.
A vintage Champagne, conversely, is a wine from a single, presumably superior year—and comes with a higher price tag. Recent top vintages include 1995, 1996, 2002 and 2008. A third designation you may see on a Champagne bottle is "prestige cuvée"; this is the very best wine produced by the Champagne grower or house. Some of the best-known examples include Dom Pérignon from Moët & Chandon, Cristal from Louis Roederer and Taittinger Comtes de Champagne, though some are made by smaller houses like Pol Roger (Cuvée Sir Winston Churchill) and growers like Pierre Gimonnet (Special Club).
The great success and global recognition of Champagne rests largely on the work of the "brands"—big Champagne houses such as Moët & Chandon, Veuve Clicquot and Perrier-Jouët. They account for the vast majority of sales and just about all the promotional dollars. Instead of large marketing budgets and celebrity spokesmen, the growers of Champagne have prospered thanks to this marketing and a cadre of impassioned sommeliers.