The
Winemaking Process
The process of turning grapes
into wine is called vinification. Usually, the first step in the modern
vinification process is the separation of the stems from the grapes.
The next step is to crush the grapes to release the juice. If a white
wine is being produced, the juice is separated from the skins at this
point. If a red wine is being made, the juice is left with the skins
to extract colors, tannins, and other substances.
After the grapes have been
crushed into must, the vinification process continues with alcoholic
fermentation. Yeast is added to the must, which consumes the sugars
in the grape juice, and converts them to alcohol. Fermentation usually
takes place in temperature controlled, stainless steel tanks. When the
fermentation has converted the must to wine, the sediments are allowed
to settle to the bottom of the tank. The wine is then pumped off to
other containers for the next step in the process.
Most red wines, and some
whites, undergo a second fermentation induced by bacteria rather than
yeasts. This fermentation changes the malic acid into softer lactic
acid, which lowers total acidity and makes wines seem rounder and fuller
in flavor.
Many
white wines and some reds to be sold young are settled and clarified
in large containers for about six months. For more depth and complexity,
some wines are aged in wooden casks or barrels. Wines are clarified
naturally by racking. Sediments are allowed to settle to the bottom
of the container, and the wine is periodically pumped into clean barrels.
At this point, wines are
usually stabilized by refrigeration and filtering and are then bottled
and stored for one to three months to balance their components. Wines
aged in wooden barrels are often fined using egg whites or protein compounds
and sometimes lightly filtered before bottling to remove any suspended
particles.
Bottled wines are usually
stored horizontally for up to a year before being sold to acquire harmony
and to begin development of the tertiary aromas known as the bouquet.
Some wines improve for a 10 years or more in the bottle, gaining a unique
complexity in flavor and bouquet.
