A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Acetic Acid
All wines contain acetic acid, or vinegar, but usually the amount is quite small—from 0.03 percent to 0.06 percent—and not perceptible to smell or taste. Once table wines reach 0.07 percent or above, a sweet-sour vinegary smell and taste becomes evident. At low levels, acetic acid can enhance the character of a wine, but at higher levels (over 0.1 percent), it can become the dominant flavor and is considered a major flaw. A related substance, ethyl acetate, contributes a nail polish-like smell.

Acid
A compound present in all grapes and an essential component of wine that preserves it, enlivens and shapes its flavors and helps prolong its aftertaste. There are four major kinds of acids–tartaric, malic, lactic and citric–found in wine. Acid is identifiable by the crisp, sharp character it imparts to a wine.

Acidic
Used to describe wines whose total acid is so high that they taste tart or sour and have a sharp edge on the palate.

Acidification
The addition of acid to wine by a winemaker. The goal is to balance the wine’s soft components (sugar, alcohol and fruit). It is legal in some areas—such as Bordeaux, Burgundy, Australia and California—to correct deficient acidity by adding acid. When overdone, acidity leads to unusually sharp, acidic wines. It is illegal in Bordeaux and Burgundy to both chaptalize (add sugar to) and acidify a wine.

Acidity
Identified as the crisp, sharp character in a wine. The acidity of a balanced dry table wine is in the range of 0.6 percent to 0.75 percent of the wine’s volume.

Acrid
Describes the harsh, bitter taste or pungent, nose-biting odor caused by excessive amounts of sulfur added during winemaking. When used properly, sulfur dioxide plays a beneficial role in winemaking; it kills unwanted organisms, protects wines from spoilage and cleans equipment.

Aeration
This process of encouraging a wine to absorb oxygen is also called breathing. Simply pulling the cork out of a bottle may not allow for sufficient air contact; decanting or even swirling the wine in a glass are preferred methods. The goal is to allow the wine to open up and develop, releasing its aromas into the air. Ten to 30 minutes of aeration can help open tight young red wines that are meant to age. Some wines can also develop off odors or a bottle stink that blows off with a few minutes of aeration. Since older (15-plus years) red wines are more delicate and can lose their fruit during aeration, aeration is not recommended; the wines can evolve quite quickly in the glass.

Aftertaste
The taste or flavors that linger in the mouth after the wine is tasted, spit or swallowed. The aftertaste or “finish” is the most important factor in judging a wine’s character and quality. Great wines have rich, long, complex aftertastes.

Ageworthy
Describes the small number of top wines that have sufficient flavor, acidity, alcohol and tannins to gain additional complexity with time in the bottle. Most popular wines are meant to be enjoyed shortly after release and will only diminish with age.

Aggressive
Unpleasantly harsh in taste or texture, usually due to a high level of tannin or acid.

Aging
Storage in barrels, tanks or bottles for a period of time allows wine components to knit together or harmonize and develop additional complexity, sometimes referred to as secondary and tertiary aromas and flavors.

Alcohol
Ethyl alcohol, a chemical compound formed by the action of natural or added yeast on the sugar content of grapes during fermentation.

Alcohol by Volume
As required by law, wineries must state the alcohol level of a wine on its label. This is usually expressed as a numerical percentage of the volume. For table wines the law allows a 1.5 percent variation above or below the stated percentage as long as the alcohol does not exceed 14 percent. Thus, wineries may legally avoid revealing the actual alcohol content of their wines by labeling them as “table wine.”

Alcoholic
Used to describe a wine that has too much alcohol for its body and weight, making it unbalanced. A wine with too much alcohol will taste uncharacteristically heavy or hot as a result. This quality is noticeable in aroma and aftertaste.

Alcoholic Fermentation
Also called primary fermentation, this is the process in which yeasts metabolize grape sugars and produce alcohol, carbon dioxide and heat. The final product is wine.

Allier
A forest in France that produces oak used for wine barrels.

American Oak
An alternative to French oak for making barrels in which to age wine. Marked by strong vanilla, dill and cedar notes, it is used primarily for aging Cabernet, Merlot and Zinfandel, for which it is the preferred oak. It’s less desirable, although used occasionally, for Chardonnay or Pinot Noir. New American oak barrels can be purchased for about half the price of French oak barrels.

American Viticultural Area (AVA)
A delimited, geographical grapegrowing area that has officially been given appellation status by the Alcohol and Tobacco, Tax and Trade Bureau (TTB). Two examples of AVAs are Napa Valley and Sonoma Valley.

Ampelography
The study of and identification of grape varieties.

Amtliche Prüfungsnummer
The tracking number that appears on German wines indicating that the wine has passed a number of tests and meets all German legal requirements.

Anthocyannins
The pigments found in red grape skins that give red wine its color.

Appearance
Refers to a wine’s clarity, not color. Common descriptors refer to the reflective quality of the wine; brilliant, clear, dull or cloudy for those wines with visible suspended particulates.

Appellation
Defines the area where a wine’s grapes were grown, such as Bordeaux, Gevrey-Chambertin, Alexander Valley or Russian River Valley. Regulations vary widely from country to country. In order to use an appellation on a California wine label, for example, 85 percent of the grapes used to make the wine must be grown in the specified district.

Appellation d’Origine Contrôlée (AOC or A.O.C.)
The French system of appellations, begun in the 1930s and considered the wine world’s prototype. To carry an appellation in this system, a wine must follow rules describing the area the grapes are grown in, the varieties used, the ripeness, the alcoholic strength, the vineyard yields and the methods used in growing the grapes and making the wine.

Aroma
Aromas are smells, which originate with the grapes, in contrast to bouquet, which defines smells acquired during bottle-aging. In the process of sensory evaluation, purists also discriminate between wine’s aroma (smells sensed by sniffing the wine through the nose) and its flavor (smells sensed via the mouth).

Aromatic
Describes a wine with intense, often floral, aromas. Particularly aromatic varieties include Gewürztraminer, Muscat and Viognier.

Aspersion
The process of using water sprinklers to protect budding vines from late-spring frosts. The sprinklers are turned on just as temperatures dip below freezing, forming a protective barrier of ice that shields young vine buds from colder temperatures.

Assemblage
French term for blending various lots of wine before bottling, especially in Champagne.

Astringent
Describes wines that leave a coarse, rough, furry or drying sensation in the mouth. Astringency is usually attributed to high tannin levels found in some red wines (and a few whites). High tannin levels are frequently found in Cabernet Sauvignon and Cabernet Franc.

Auslese
German classification based on the ripeness level and sugar content of the grapes. Auslesen are made from individually-selected bunches of very ripe grapes that have higher sugar concentrations than those selected for spätlesen, but lower than those selected for beerenauslesen. Auslesen are nearly always sweet wines but can be fermented in drier styles.

Austere
Used to describe relatively hard, high-acid wines that lack depth and roundness. Usually said of young wines that need time to soften, or wines that lack richness and body.

Awkward
Describes a wine that has poor structure, is clumsy or is out of balance.