special qualities and how they are produced.
Sparkling Wines: Champagne and Others
Sparkling wines delight by emitting bubbles
that catch the light and prick the tongue. The
bubbles come from the wine’s considerable
dissolved reserves of carbon dioxide gas, a
by-product of yeast metabolism that
ordinarily escapes into the air from the
surface of the fermenting wine. To make a
sparkling wine, the wine is confined under
pressure — either in the bottle or in special
tanks — so that the carbon dioxide can’t
escape as it’s produced, and instead comes to
saturate the liquid. A bottle of Champagne
holds a gas pressure of 3–4 atmospheres,
somewhat higher than the pressure in car tires,
and contains about six times its volume in
carbon dioxide!
When we remove the cork and thus relieve
the pressure, the excess carbon dioxide leaves
the solution in the form of gas bubbles. The