HOW BORDEAUX IS MADE

In Bordeaux, the vintners select and vinify separately the different grape varieties that will eventually be blended into the final wine. While the precise vinification process varies between appellations and châteaux according to each vintner's secret recipe, following is a general guide to how Bordeaux wines are made.


Red and Non-Sweet White Wine

From Harvest to Juice

Alcoholic Fermentation
This is when grape sugar is converted into alcohol by natural yeast found in grape skins (or sometimes by the addition of special yeast strains).

Red: Alcoholic fermentation takes place over a period of 5 to 10 days. Most red wines are fermented to complete dryness, with little or no residual sugar remaining.

White: Alcoholic fermentation for white wine lasts longer than for red, 12 to 15 days, and at cooler temperatures so that more of the juices' natural aromas are retained. Dry white wines are made by letting all of the grape sugar turn into alcohol.


Maceration
Red: Some producers leave the wine to soak with the skins, pulp, pips, and dead yeast cells (together called "marc") for up to 18 days during which time the alcohol extracts pigment, tannins, and flavors from the marc.


Separation
Red: Fermented grape juice (called free-run wine) is separated from the marc. Then the marc is pressed to extract any remaining wine. This wine, called vin de presse, has highly concentrated flavors, tannins, and colors and may be blended back into the wine to achieve the desired style and flavor.


Malolactic Fermentation
Sometimes called and also known as Secondary Fermentation This is an optional fermentation more often used for red wine production than white. It sometimes occurs naturally, or can be induced by the wine maker at the same time as or after alcoholic fermentation. Malolactic fermentation converts malic acid to lactic acid which lowers a wine's acidity and makes it softer and more pleasant to drink. In white wine production, malolactic fermentation risks lowering the wine's acidity too much, so it must be accomplished with great skill and subtlety.


Clarification
Next the wine is racked, an operation which separates the clear wine from any remaining particles from the marc. An alternative way to clarify a wine is to introduce a substance (called a "fining agent") which causes solid particles to fall to the bottom of the container for removal. Egg whites are commonly used as a fining agent. Filtration and the use of a centrifuge are other clarification methods.


Blending
The wine maker combines wines made from different grape varieties and vats to created the desired bouquet, style, and flavor of wine.


Aging and Bottling
Red: Wine may be aged for up to two years in oak barrels which imparts structure, additional tannin and flavor. Finally, the wine is bottled and stored in cellars for further aging or shipped to distributors.
 

White: Aging is much shorter for white wines than for reds. Some may be aged for up to one year in oak barrels which give the wine additional structure and flavor. However, most dry white wines are bottled within a year after harvest.



Sweet White Wine
Harvest Time

Most of the grapes used for sweet white wines are affected with noble rot. It is caused by a fungus, Botrytis cinera, which allows water to evaporate from the grape. The result is grapes with a high concentration of sugar, 30 to 40 percent. Grapes are usually picked in several waves to ensure that only the ripest and sweetest ones are used.

Fermentation and Production
Sweet white wine is made similarly to dry white wine except that alcoholic fermentation is stopped before all of the grape sugar is turned into alcohol. The result is a residual (unfermented) sugar of up to 12 percent in the finished wine.


Aging and Bottling
After blending, sweet wines are usually aged for up to three years in oak barrels to increase richness before bottling and distribution.