How do those bubbles get in the bottle? For some lower-end wines, it's the same way sodas are carbonated, through the introduction of carbon dioxide gas. But higher-end wines are crafted utilizing a more expensive and complex technique named after the finest sparkling wines, "méthode champenoise."
Whether it's sparkling Shiraz from Australia, sparkling Riesling from Austria, Cava from Spain or Champagne from France, all wines begin in the vineyard. Soil, climate, weather and cultural practices affect the quality and character of the fruit. Once the grapes are harvested, they are placed in a destemmer/crusher, which separates the stems from the fruit and breaks up the berries. The stems are then discarded leaving a "must," a combination of juice, seeds, pulp and skins. At this point, the process for red and white wine production differs.
The juice from both red and white wine grapes is without color. Red wines are fermented together with the grape skins and seeds. The skins float to the top forming a cap during fermentation and must be moistened regularly with juice to extract color and flavors. Red wines are usually fermented for a period of five to ten days.
For whites, the skins and seeds are usually removed from the must after only a few hours. The skins are pressed to extract all the remaining juice. The juice is filtered, then placed in stainless steel tanks or oak barrels where the wine will ferment following the addition of yeast. White wine fermentation lasts from three days to three weeks. When fermentation has run its course, the vintner will stop the process and filter the wine to remove solids and yeast remnants.
Sparkling wines are made from red or white still wines, such as Chenin Blanc, French Colombard, Chardonnay or Pinot Noir, which serve as a base for the next stage of this unique winemaking process. For Champagnes, which must meet many strict regulations as opposed to other sparkling wines, Chardonnay, Pinot Noir and Pinot Meunier grapes are used almost exclusively. (You may see Champagne grapes at the supermarket, but they are not used to make Champagne!) A "triage" — a blend of the base wine, yeast nutrient and a source of sugar — is added to the base wine and the mixture is fermented a second time in a sealed container which traps carbon dioxide producing the effervescence or bubbles. The second fermentation usually takes four to eight weeks.
The new sparkling wine is aged in the bottle interacting with the dead yeast cells called lees, which affects the flavor and texture of the final product. Non-vintage Champagnes must age a minimum of 15 months on their lees, while vintage Champagnes (those made from a single year's harvest) must age at least three years. Then the bottles are turned upside-down and turned frequently, causing the lees to fall into the neck of the bottle. The sediment is disgorged, and the bottles are topped off, corked and capped. After a short rest, they are ready to help you celebrate.
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