Oxidized: Describes wine that has been exposed too long to air and taken on a brownish color, losing its freshness and perhaps beginning to smell and taste like Sherry or old apples. Oxidized wines are also called maderized or sherrified.
Nutty: Used to describe oxidized wines. Often a flaw, but when it's close to an oaky flavor it can be a plus.
Reduced: Commonly used to describe a wine that has not been exposed to air and has developed stinky aromas due to reductive chemical reactions (as opposed to oxidation). Reduced notes in a wine generally result from the presence of volatile sulfur compounds, or mercaptans; these notes include rotten eggs, rubber, struck matches, sewage and even skunk. These off aromas may dissipate after exposure to air through decanting or swirling the wine in the glass.
Fill Level: The amount of wine in a bottle is gauged by its height in the bottle. Common descriptors are good fill, high shoulder (the wine level is even with the sloping part of the bottle just below the neck), or low shoulder. Important since fill level is an indicator of the wine’s condition and whether it has been properly stored. The air space in the bottle, called ullage, can cause harmful oxidation.
Micro-oxygenation: This technique, used almost exclusively on red wines, allows winemakers to control the amount of oxygen that wines in tank are exposed to. The apparatus involves chambers connected by tubes and valves to an oxygen tank. Small, measured amounts of oxygen are allowed to pass through the wine via a porous stone or ceramic plate at or near the base of the tank. The benefits of this type of oxygen exposure include prevention of oxidation and reduction as well as promotion of healthy yeast cultures, which prevent stuck fermentations. Micro-oxygenation is also believed to soften tannins and, in conjunction with the use of oak chips, is frequently practiced as an alternative to oak barrel aging.
Devatting: Also known as délestage, the oxidative winemaking process in which, after the cap of grape musts, skins, seeds and stems forms on the top of a vat of fermenting wine, the wine is drained through a valve at the base of the tank into another vat and reserved while the remaining solids are allowed to drain for a few hours. The reserved wine is then pumped back into the original tank over the top of the drained skins, seeds and stems. Like punch downs and pump overs, the purpose of devatting is to increase the extraction of color, flavor, tannins and aromas from the solids, as well as aerate the fermenting wine.
Oloroso: Oloroso is the darkest, richest category of dry Sherry. The wines are aged oxidatively, without the flor yeast cap that protects finos and amontillados, and may have alcohol levels up to 20 percent. The wines have a nutty aroma and flavor, and serve as the base for cream Sherry dessert wines.
Amontillado: Amontillado is a category of Sherry which begins aging in the same manner as a fino Sherry, with a flor yeast cap to protect from oxidation and keep the wine fresh-tasting, but amontillado is then exposed to oxygen, allowing the wine to darken, becoming richer than a fino but still lighter than an oloroso.
Flor: Flor is the Spanish term for a cap of yeast that forms over Sherry wine as it ages in barrel, protecting the wine from oxidation.
Oxidative: Refers to winemaking practices that deliberately expose the wine to oxygen, such as the use of open-top fermentors and racking. Traditional winemaking exposes the wine to some air, but does not result in oxidized notes. An aggressively oxidative approach can result in nutty notes, as seen in wines such as Sherry or vin jaunes from the Jura.
Reductive: Refers to winemaking practices that reduce a wine's exposure to oxygen, such as the use of stainless steel tanks and inert gases to minimize contact with air. This is done to maximize a wine's fresh fruit flavors. However, in some cases it can result in "reduced" aromas, considered a flaw.