by Alexander J. Pandell, Ph.D.
Champagne was developed in France about 300 years ago from a process involving lots of chemistry and many tedious physical manipulations. The sparkling wine we call "champagne" comes from the Champagne region of France, a 3 hour drive east of Paris. In the U.S., most Champagne-like wines are called "sparkling wines" in deference to the French who prefer that other countries not refer to their sparkling wines as "Champagne." The history of Champagne dates to about 1700 AD and a monk cellarmaster at the Abbey of Hautvillers near the city of Reims, the "capital" of the Champagne region. As the story goes, a monk named Dom Pérignon was making wine for his colleagues when, unbeknownst to him, he failed to complete the fermentation before bottling and corking the wine. During the cold winter months the fermentation remained dormant, but when spring arrived the contents of the sealed bottles began to warm and fermentation resumed producing carbon dioxide that was trapped in the bottle. Later that spring Dom noticed that bottles of wine in the cellar were exploding, so he opened one that was intact and drank, declaring "Come quickly! I'm drinking stars!" Thus, Champagne was born and named after the region where it was discovered. Today Möet & Chandon make a Champagne named in honor of Dom Pérignon, the serendipitous inventor of Champagne. A bronze statute of the famous monk stands outside Möet & Chandon in Epernay, France.
In the U.S. the legal definition of sparkling wine is one which contains 0.392 g of carbon dioxide per 100 mL of wine, the equivalent of about one atmosphere of gas. Most Champagnes contain about four atmospheres of carbon dioxide. The legal distinction is important because sparkling wine is taxed at about $3.70 per gallon while "still" wine is taxed at about $0.37 per gallon!
Today, the production of Champagne is quite different from Dom Pérignon's accidental discovery. If the sparkling wine is produced outside of Champagne, France, but is made by the "French Method," it is usually labeled "Méthode Champenoise." This is true of most American sparkling wines. Méthode Champenoise, which is the method used in Champagne, involves several distinct steps.
The key reaction of winemaking is alcoholic fermentation, the conversion of sugar into alcohol and carbon dioxide by yeast. The maximum amount of alcohol attained through alcoholic fermentation is about 15% because the yeast cells are killed by high alcohol concentration. The maximum alcohol content can be determined by multiplying 0.55 times the percent sugar initially present in the grape juice before fermentation. For example, if 24% sugar is initially present, about 13% (0.55 x 24) alcohol will be realized. Most still wines (i.e., table wines) contain 12 to 14% alcohol.
The key process in producing Champagne is a SECOND fermentation that occurs in a sealed bottle. The entire process is described below.
SELECTING THE CUVÉE (La Cuvée)
The cuvée is the base wine selected to make the Champagne. The most expensive Champagnes are made from cuvées from selected vineyards in the Champagne region. Cuvées can be from a pure grape variety, such as Chardonnay or Pinot Noir, or can be a mixture of several grape varieties. Chardonnay is a white grape variety with white juice, Pinot Noir a red grape variety with WHITE juice. Pinot Meunier, a relative of Pinot Noir, also is used extensively. The slight rust color imparted to some Champagne results from using Pinot Noir cuvées that acquire some red color from contact with the skins. The longer the juice remains in contact with the skins, the darker red it becomes. If a Champagne is made exclusively from Chardonnay, it is called "blanc de blanc," white wine from white grapes. Most Champagne is made from mixed cuvees. The alcohol content of the cuvee is usually around 10%.
After the cuvée is selected, sugar, yeast, and yeast nutrients are added and the entire concoction, called the tirage, is put in a thick walled glass bottle and sealed with a bottle cap. Approximately four grams of sugar per liter of wine will produces one atmosphere of carbon dioxide. Since Champagne contains approximately six atmospheres of gas, 24 g of sugar are added per liter of base wine. After fermentation, and subsequent manipulations, the final product ends up with about four atmospheres of carbon dioxide. The tirage is placed in a cool cellar (55-60°F), and allowed to slowly ferment, producing alcohol and carbon dioxide. Since the bottle is sealed, the carbon dioxide cannot escape, and,thereby producing the sparkle of Champagne.
AGING ON DEAD YEAST
As the fermentation proceeds, yeast cells die and after several months, the fermentation is complete. However, the Champagne continues to age in the cool cellar for several more years resulting in a toasty, yeasty characteristic. During this aging period, the yeast cells split open and literally spill their guts into the solution imparting complex, yeasty flavors to the Champagne. The best and most expensive Champagne is aged for five or more years.
RIDDLING (Le Remuage)
After the aging process is complete, the dead yeast cells are removed through a process known as riddling. The Champagne bottle is placed upside down in a holder at a 75° angle. Each day the riddler comes through the cellar and turns the bottle 1/8th of a turn while keeping it upside down. This procedure forces the dead yeast cells into the neck of the bottle where they are subsequently removed. A riddler typically handles 20,000 to 30,000 bottles per day.
The Champagne bottle is kept upside down while the neck is frozen in an ice-salt bath. This procedure results in the formation of a plug of frozen wine containing the dead yeast cells. The bottle cap is then removed and the pressure of the carbon dioxide gas in the bottle forces the plug of frozen wine out leaving behind clear Champagne. At this point the DOSAGE, a mixture of white wine, brandy, and sugar, is added to adjust the sweetness level of the wine and to top up the bottle.The bottle is then corked and the cork wired down to secure the high internal pressure of the carbon dioxide.The sweetness levels of Champagne range very dry (ultra brut) to very sweet (doux), with brut being the most common.
Many Champagne houses produce "luxury cuvées," their best and most expensive wines. Dom Pérignon is the luxury cuvée of Möet & Chandon; Cristal is pride of Roederer. Bollinger produces R.D. or "recently disgorged" wines. For example, you can purchase a 1982 Bollinger R.D. that was disgorged in April 1991, nine years after being placed in the bottle.
As you can see, Champagne is a labor intensive process. Sparkling wine made in the U.S. by this method can be labeled "fermented-in-this-bottle", or "Méthode Champenoise." But not surprisingly, shortcuts to this procedure have been developed such as the Charmat bulk process, named after the inventor of the large stainless steel tank used in place of individual bottles. You can be the judge of the two processes by comparing bulk processed sparkling wine to "Méthode Champagnoise."
Now that you know the story, the comparative evaluation of Champagne and Sparkling wine becomes a more interesting endeavor.
The Alchemist's Wine Perspective™