Glossary

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	The tart (or in excess, sour) quality that is wine's natural acidity. 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. It is required for proper balance; too much or too little constitutes a flaw.
Acidity	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. It is legal in some areas--such as Bordeaux and Burgundy, Australia and in California--to correct deficient acidity by adding acid. When overdone, it leads to unusually sharp, acidic wines. However, it is illegal in Bordeaux and Burgundy to both chaptalize and acidify a wine. See also chaptalization.
Aeration	The process of letting a wine "breathe" in the open air, or swirling wine in a glass. It's debatable whether aerating bottled wines (mostly reds) improves their quality. Aeration can soften young, tannic wines; it can also fatigue older ones.
Alcohol	Produced by the yeast fermentation of the sugar content of grapes. Contributes to the wine's body and texture, which is one reason why non-alcoholic wines don't taste natural. Wine with a low alcohol level might be too sweet because not enough of the grape's sugar was converted. This results in residual sugar, an undesirable trait in some wines. Wines with excessive alcohol are characterized by a burning sensation in the mouth and are, in fact, referred to as hot.
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."
American Oak	Increasingly popular as an alternative to French oak for making barrels in which to age wine as quality improves and vintners learn how to treat the wood to meet their needs. 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. Many California and Australia wineries use American oak, yet claim to use French oak because of its more prestigious image. American oak barrels sell in the $250 range, compared to more than $500 for the French ones. See also French oak.
American Viticultural Area (AVA)	A delimited, geographical grape-growing area that has officially been given appellation status by the Bureau of Alcohol, Tobacco and Firearms. Two examples are Napa Valley and Sonoma Valley. See also viticultural area.
Ampelography	The study of the classification of grape varieties.
Aperitif	A wine-based product to be drunk before a meal to whet one's appetite, such as Vermouth, Lillet and Dubonnet.
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. See also appellation d'origine controlée.
Appellation D'origine Controlee (AOC)	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.
Barrel Fermented	Signifies wine that has been fermented in small casks (usually 55-gallon oak barrels) instead of larger tanks. Advocates believe that barrel fermentation contributes greater harmony between the oak and the wine, increases body and adds complexity, texture and flavor to certain wine types. Its liabilities are that more labor is required and greater risks are involved. It is mainly used for whites.
Bin Number	See also cask number.
Blanc De Blancs	"White of whites," meaning a white wine made of white grapes, such as Champagne made of Chardonnay.
Blanc De Noirs	White of blacks, white wine made of red or black grapes, where the juice is squeezed from the grapes and fermented without skin contact. The wines can have a pale pink hue. E.G., e.g., Champagne that is made from Pinot Noir or Pinot Meunier.
Botrytis Cinerea	Called the "Noble Rot." A beneficial mold or fungus that attacks grapes under certain climatic conditions and causes them to shrivel, deeply concentrating the flavors, sugar and acid. Some of the most famous examples come from Sauternes (Chateau d'Yquem), Germany and Tokay.
Brix	A measurement of the sugar content of grapes, must and wine, indicating the degree of the grapes' ripeness (meaning sugar level) at harvest. Most table-wine grapes are harvested at between 21 and 25. To get an alcohol conversion level, multiply the stated Brix by .55.
Brut	A general term used to designate a relatively dry-finished Champagne or sparkling wine, often the driest wine made by the producer.
Carbonic Maceration	Fermentation of whole, uncrushed grapes in a carbon dioxide atmosphere. In practice, the weight of the upper layers of grapes in a vat will break the skins of the lowest layer; the resultant wine is partly a product of carbonic maceration and partly of traditional fermentation of juice.
Cask Number	A term sometimes used for special wines, as in Stag's Leap Wine Cellars Cask 23, often applied to ordinary wines.
Cellared By	Means the wine was not produced at the winery where it was bottled. It usually indicates that the wine was purchased from another source.
Chaptalization	The procedure of adding sugar to grape juice or MUST (see "Must") prior to or during FERMENTATION; also called sugaring. Common in northern European countries, where the cold climates may keep grapes from ripening, but illegal in southern Europe (including southern France and all of Italy) and California. It is legal, with certain restrictions, in Germany and northern France.
Charmat	Mass production method for sparkling wine. Indicates the wines are fermented in large stainless steel tanks and later drawn off into the bottle under pressure. Also known as the "bulk process." See also méthode champenoise.
Clone	A group of vines originating from a single, individual plant propagated asexually from a single source. Clones are selected for the unique qualities of the grapes and wines they yield, such as flavor, productivity and adaptability to growing conditions.
Cold Stabilization	A clarification technique in which a wine's temperature is lowered to 32° F, causing the tartrates and other insoluble solids to precipitate.
Crush	Harvest season when the grapes are picked and crushed.
Cult Wine	Rare wine produced by a vinyard in small quantity which is well known to collectors and sold for a high price.
Cuvee	Typically means a blend or special lot of wine.
Decanting	A process for separating the sediment from a wine before drinking. Accomplished by slowly and carefully pouring the wine from its bottle into another container.
Demi-sec	In the language of Champagne, a term relating to sweetness. It can be misleading; although demi-sec means half-dry, demi-sec sparkling wines are usually slightly sweet to medium sweet.
Destemming	The process of removing grape stems prior to fermentation, to avoid adding tannins from the stems to the wine.
Disgorgement	A step in the traditional process of sparkling wine production wherein frozen sediment is removed from the neck of the bottle.
Domaine	A French term for a wine estate.
Dosage	In bottle-fermented sparkling wines, a small amount of wine (usually sweet) that is added back to the bottle once the yeast sediment that collects in the neck of the bottle is removed.
Drying Out	Losing fruit (or sweetness in sweet wines) to the extent that acid, alcohol or tannin dominate the taste. At this stage the wine will not improve.
Dumb	Describes a phase young wines undergo when their flavors and aromas are undeveloped. See also "closed".
Early Harvest	Denotes a wine made from early-harvested grapes, usually lower than average in alcoholic content or sweetness.
Enology	The science and study of winemaking. Also spelled oenology.
Ethyl Acetate	A sweet, vinegary smell that often accompanies acetic acid. It exists to some extent in all wines and in small doses can be a plus. When it is strong and smells like nail polish, it's a defect.
Evolution	The development of complex and desirable aromas and flavors (see "bouquet") in age worthy wine cellared under appropriate temperature conditions.
Extra Brut	The very driest sparkling wine, with sugar content of 0-6 grams per liter.
Extract	Richness and depth of concentration of fruit in a wine. Usually a positive quality, although high extract wine can also be highly tannic.
Extra-dry	A common Champagne term not to be taken literally. Most Champagnes so labeled are sweet.
Fermentation	The process by which yeast converts sugar into alcohol and carbon dioxide; turns grape juice into wine.
Field Blend	When a vineyard is planted to several different varieties and the grapes are harvested together to produce a single wine, the wine is called a field blend.
Filtering	The process of removing particles from wine after fermentation. Most wines unless otherwise labeled are filtered for both clarity and stability.
Fining	A technique for clarifying wine using agents such as bentonite (powdered clay), gelatin or egg whites, which combine with sediment particles and cause them to settle to the bottom, where they can be easily removed.
Fortified	Denotes a wine whose alcohol content has been increased by the addition of brandy or neutral spirits.
Fragile	An older wine, fully mature, of such age that it's declining.
Frappé	Iced, chilled.
Free-run Juice	The juice that escapes after the grape skins are crushed or squeezed prior to fermentation.
French Oak	The traditional wood for wine barrels, which supplies vanilla, cedar and sometimes butterscotch flavors. Used for red and white wines. Much more expensive than American oak, it can cost more than $500 per barrel, as opposed to $250 for American.
Futures	The right to buy a certain wine before it is actually made.
Green Harvest	The trimming of unripe grapes to decrease crop yields, thereby improving the concentration of the remaining bunches.
Grown, Produced and Bottled	Means the winery handled each aspect of wine growing.
Jug Wine	Jug wine is wine bottled in a jug, which often has a handle. It is generally regarded as less than acceptable by wine aficionados. Jug wines are usually drunk for intoxication rather than pleasure. Common brands of jug wine include Boone's Farm, Gallo, and Carlo Rossi.
Kosher wine	A wine made according to strict Jewish rules under rabbinical supervision.
Late Harvest	On labels, indicates that a wine was made from grapes picked later than normal and at a higher sugar (Brix) level than normal. Usually associated with botrytized and dessert-style wines.
Lees	Sediment remaining in a barrel or tank during and after fermentation. Often used as in sur lie aging, which indicates a wine is aged "on its lees." See also sur lie.
Limousin	A type of oak cask from Limoges, France. See also French oak.
Malolactic Fermentation	A secondary fermentation occurring in most wines, this natural process converts malic acid into softer lactic acid and carbon dioxide, thus reducing the wine's total acidity. Adds complexity to whites such as Chardonnay and softens reds such as Cabernet and Merlot.
Mature	Ready to drink.
Meritage	An invented term, used by California wineries, for Bordeaux-style red and white blended wines. Combines "merit" with "heritage." The term arose out of the need to name wines that didn't meet minimal labeling requirements for varietals (i.e., 75 percent of the named grape variety). For reds, the grapes allowed are Cabernet Sauvignon, Merlot, Cabernet Franc, Petite Verdot and Malbec; for whites, Sauvignon Blanc and Sémillon. Joseph Phelps Insignia and Flora Springs Trilogy are examples of wines whose blends vary each year, with no one grape dominating.
Methode Champenoise	The labor-intensive and costly process whereby wine undergoes a secondary fermentation inside the bottle, creating bubbles. All Champagne and most high-quality sparkling wine is made by this process. See also charmat.
Must	The unfermented juice of grapes extracted by crushing or pressing; grape juice in the cask or vat before it is converted into wine.
Negociant (negociant-eleveur)	A French wine merchant who buys grapes and vinifies them, or buys wines and combines them, bottles the result under his own label and ships them. Particularly found in Burgundy. Two well-known examples are Joseph Drouhin and Louis Jadot.
New World Wines	A term that groups all those wines which come from the southern hemisphere, as well as those from North America. The U.S. and Argentina are both high volume producers, with California producing 95% of the U.S. total. Generally, new world wines are created from international grape varieties.
Noble Rot	See Botrytis cinerea.
Nonvintage	Wine blended from more than one vintage. This allows the vintner to keep a house style from year to year. Most Champagnes and sparkling wines are nonvintage. Also, Sherry and the nonvintage Ports, the tawnies and the rubies.
Nouveau	A style of light, fruity, youthful red wine bottled and sold as soon as possible. Applies mostly to the Beaujolais.
Off-dry	This Indicates a slightly sweet wine in which the residual sugar is barely perceptible 0.6 percent to 1.4 percent.
Peak	The time when a wine tastes its best--very subjective.
Ph	A chemical measurement of acidity or alkalinity; the higher the pH the weaker the acid. Used by some wineries as a measurement of ripeness in relation to acidity. Low pH wines taste tart and crisp; higher pH wines are more susceptible to bacterial growth. A range of 3.0 to 3.4 is desirable for white wines, while 3.3 to 3.6 is best for reds.
Phylloxera	Plant louse or tiny aphids that can devastate vineyards. . The disease was widespread in both Europe and California during the late 19th century, and returned to California in the 1980s.
Press Wine (or Pressing)	The juice extracted under pressure after pressing for white wines and after fermentation for reds. Press wine has more flavor and aroma, deeper color and often more tannins than free-run juice. Wineries often blend a portion of press wine back into the main cuvée for added backbone.
Private Reserve	This description, along with Reserve, once stood for the best wines a winery produced, but lacking a legal definition many wineries use it or a spin-off (such as Proprietor's Reserve) for rather ordinary wines. Depending upon the producer, it may still signify excellent quality.
Racking	The practice of moving wine by hose from one container to another, leaving sediment behind. For aeration or clarification.
Reduced	Commonly used to describe a wine that has not been exposed to air.
Residual Sugar	Unfermented grape sugar in a finished wine. A technical term for the natural sugar that remains in naturally sweet wines after the conversion of fruit sugars into alcohol.
Sommelier	A restaurant employee who orders and maintains the wines sold in the restaurant and usually has extensive knowledge about wine and food pairings.
Structure	The interaction of elements such as acid, tannin, glycerin, alcohol and body as it relates to a wine's texture and mouthfeel. Usually preceded by a modifier, as in "firm structure" or "lacking in structure."
Sur Lie	Wines aged sur lie (French for "on the lees") are kept in contact with the dead yeast cells and are not racked or otherwise filtered. This is mainly done for whites, to enrich them (it is a normal part of fermenting red wine, and so is not noted).
Tannin	The mouth-puckering substance--found mostly in red wines--that is derived primarily from grape skins, seeds and stems, but also from oak barrels. Tannin acts as a natural preservative that helps wine age and develop.
Tartaric Acid	The principal acid in wine.
Tartrates	Harmless crystals of potassium bitartrate that may form in cask or bottle (often on the cork) from the tartaric acid naturally present in wine.
Terroir	Derived from the French word for Earth, "Terre." The over all environment within which a given varietal grows. A " terroir " is a group of vineyards (or even vines) from the same region, belonging to a specific appellation, and sharing the same type of soil, weather conditions, grapes and wine making savoir-faire, which contribute to give its specific personality to the wine.
Verticals	Different vintages from the same producer.
Viniculture	The science or study of grape production for wine and the making of wine.
Vintage Date	Indicates the year that a wine was made. In order to carry a vintage date in the United States, for instance, a wine must come from grapes that are at least 95 percent from the stated calendar year. See also nonvintage.
Vinted By	Largely meaningless phrase that means the winery purchased the wine in bulk from another winery and bottled it.
Vintner	Translates as wine merchant, but generally indicates a wine producer/or winery proprietor.
Vintner-grown	Means wine from a winery-owned vineyard situated outside the winery's delimited viticultural area.
Viticultural Area	Defines a legal grape-growing area distinguished by geographical features, climate, soil, elevation, history and other definable boundaries. Rules vary widely from region to region, and change often. Just for one example, in the United States, a wine must be 85 percent from grapes grown within the viticultural area to carry the appellation name. For varietal bottling, a minimum of 75 percent of that wine must be made from the designated grape variety. See also appellation d'origine controlée.
Viticulture	The cultivation, science and study of grapes.
Vitis Vinifera	Classic European wine-making species of grape. Examples include Cabernet Sauvignon and Chardonnay. Compare Vitis labrusca, North American grape species used mainly for New York state wines. For example, Concord.
Yeast	Micro-organisms that produce the enzymes which convert sugar to alcohol. Necessary for the fermentation of grape juice into wine