Grape to Glass  :  Making the Wine

After fall harvest, California’s wine-grape growers hand over the reins to the state’s world-class vintners. Red, white, sparkling and dessert wines are made using different techniques that vary on fermentation time, aging length, aging vessels (oak barrels or stainless steel tanks), temperature and more. Each decision the vintner makes influences the character and flavor of the resulting wine.

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making red wine


An astringent natural component found in grape skins and seeds that causes the dry and puckery feeling in wine, particularly red wines. Tannins often provide the wine’s structure or backbone.


Once the grape clusters have been destemmed and crushed, they head to the fermentor. Oddly enough, the juice of almost all grapes, red and white, is virtually without color. What gives wine its bold look, and flavor, are the grape skins. The heat and alcohol generated during fermentation forces the skins to act like food coloring, dying the wine a red-purple color.

Skins also provide red wine with its characteristic bold tannins, which also act as a preservative (that’s why red wines can be aged longer than white wines). Yeast is usually added to kick-start the fermentation process. Red wines are commonly fermented on their skins in temperature-controlled stainless steel tanks, but some wineries ferment reds in oak barrels or stainless steel tanks.

After fermentation, the wine is separated from the skins and is typically aged anywhere from one to three years in oak barrels. Depending on the wine varietal and style, however, a winemaker may alternatively use stainless steel, oak or redwood tanks for aging. When the winemaker determines the wine has aged properly, it can either be bottled as a single varietal or blended with other red varietals and then bottled.


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