Making Red Varietals

During red winemaking, after the grapes run through the crusher/destemmer ("a process called crush"), the juice remains with the grape skins for fermentation.  The grape skins give red wine its color, flavor and "tannins", which are the polyphenols that enable red wines to age and take on more and more complexity.  Tannins are what give your mouth that slight puckery feeling after a sip of red wine. Like with white wine, yeast is added to begin the process of fermentation, during which the natural sugars convert to alcohol.  Red wine fermentation, however, occurs at warmer temperatures that white wine fermentation.  As red wines ferment, the grape skins float to the top of the juice, forming a cap that must be resubmerged ("punch-down") or moistened with grape juice ("pump-over") in order for the juice to continue extracting color and flavor.  As with white wines, red wines may be fermented or aged in any combination of oak and stainless steel - but the use of oak is much more prevalent in red winemaking than in white winemaking, as oak characters are much less likely to overwhelm the more robust personalities of red wines.  The primary fermentation of red wines usually lasts for five to ten days, followed by malolactic fermentation, during which the tart malic acid found in fruit is converted to softer lactic acid.

It is common for red wines to be aged in oak barrels for one to two years.  As with white wines, a winemaker may choose to blend at this stage.  The wine is then finished, filtered and clarified - with egg whites, gelatin or other refining methods that remove astringent substances and proteins - before bottling.  Sulfites may also be added to prevent oxidation and bacterial spoilage.