Sparkling
wines are made from 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. (Among
premium sparkling wines, Chardonnay and Pinot Noir grapes
are used almost exclusively.) 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.
More