Oxidation
Oxidation
Oxidation is a chemical reaction that occurs when oxygen in the air comes in contact with the alcohol in wine, converting ethanol into acetaldehyde, then acetic acid. It causes wines to lose their vibrant colors: white wines become brown, red wines develop orange hues. It also reduces fresh fruit aromas and introduces nutty or vinegar notes. Although it is harmful in excess, controlled oxidation is beneficial while aging wine.
See Also
Yield
The yield signifies the amount of grapes or wine produced from a specific vineyard area, commonly measured in tons per acre in the US, or hectoliters per hectare in Europe. Lower yields are associated with better quality, while higher yields produce lighter and less concentrated wines.
Irrigation
Irrigation is the artificial application of water to vineyards to provide the necessary 25-35 inches of annual water in dry climates.
Maceration
Maceration in wine is the process of soaking crushed grape skins, seeds and stems in the juice (must) to extract color, tannins and aroma compounds.
Fermentation
Fermentation is a natural biochemichal process where yeast consumes the natural sugars in grape juice and converts them into alcohol, carbon dioxide and heat. At the end of fermentation, grape juice is converted into wine.
Dosage
Dosage is the final step in producing traditional sparkling wine (such as Champagne) where a small amount of wine and sugar, known as liqueur d'expédition is added to the wine after sediment is removed (disgorgement), just before corking.
Oak
Oak imparts flavor, aroma and texture into wines through fermentation in oak barrels. These barrels act as gentle, breathable vessels that add complex notes and improve the wine's overall structure and mouthfeel.
Crush
The Crush refers to the period in late summer or fall when harvested grapes are mechanically broken to rupture their skins and release the juice, initiating the winemaking process.
Yeast
Yeast in wine is a microscopic, single celled fungus, typically Saccharomyces cerevisiae, which triggers fermentation by transforming the sugars in must into ethanol and carbon dioxide. Yeasts are essential for converting grape juice into wine and they determine its final alcohol content, aroma and flavor profile.