ACETIC ACID
Wines contain several types of acid, but acetic is the bad one: it suggests vinegar and is sometimes referred to as volatile acidity. If present at more than minimal levels, it makes a wine unpleasant.

ACIDITY
Acid is present in all grapes, and therefore all wines. It is extremely important (particularly in white wines) in determining structure, shape and lifespan. Good acid levels can make a wine crisp and refreshing, supporting the aftertaste. Acidity also helps preserve a wine. Wines low in acidity are often described as tasting flabby.

AERATION
Letting a wine "breathe" before drinking it in order to soften the tannins, smooth out the wine, and allow the bouquet and flavors to open up. Young red wines benefit most from aeration, which is accomplished by decanting the bottle into another container; or else, by swirling the wine in a glass.

AFTERTASTE
Also called the "finish," this is the taste that remains in the mouth after the wine is swallowed. A really great wine will have a long, complex aftertaste.

AGGRESSIVE
A term used to describe a wine with harsh flavors, often the result of too much tannin or acid.

AMERICAN OAK
Along with French oak, American oak is the most widely used wood in the world to build barrels for wine aging. American oak barrels are most often used to age red wines (especially Zinfandels, Cabernets and Syrahs), Spanish Sherries, Australian red wines, Bourbon and Scotch. Less frequently utilized in the production of white wines, American oak has a different spice flavor than French oak. In fact, the flavors vary from different forests and states. Kentucky oak imparts mellower flavors, for example, than Oregon oak. Examples of two famous California wines aged in 100% American oak are the classic vintages of Beaulieu Private Reserve Cabernet Sauvignon (from the 1940's to the 1970's) and ZD Chardonnay.

AMERICAN VITICULTURAL AREA (AVA)
A particular geographical location, such as Napa Valley and Sonoma Valley, that has been officially designated a grape-growing area in the United States by the Bureau of Alcohol, Tobacco and Firearms. See also: viticultural area.

APPELLATION
A system developed by the French to regulate the authenticity of their finest wines. Appellation applies specifically to the region where the grapes were grown. The French also regulate what grapes can be grown where; what winemaking methods can be used; how large the yields can be; etc. Other countries have adopted their own versions of controlled appellations with varying success.

APPELLATION D'ORIGINE CONTROLEE (AOC)
The French system of appellations.

AROMA
The scent of a wine--frequently used interchangeably with the word "bouquet." Some tasters apply the term aroma only to the fruit-like fragrances of a young wine, and subsequently refer to the more complex smells of bottle-aged wines as bouquet.

ASTRINGENT
The mouth puckering sensation caused by wines (usually reds) that are high in tannin. Sometimes astringency can be appealing in a wine and favorably complement food. Astringency tends to decline with bottle age.

AUSTERE
Describes high-acid wines; sometimes used in reference to young wines.

BACKBONE
Often used to describe wines with good acidity and structure.

BAKED
A characteristic-usually not complementary-of wines produced from very ripe and over-ripe grapes.

BALANCE
Describes a wine with harmonious elements, in reference to the balance of acids, tannins and fruit.

BALTHAZAR
A huge bottle that holds 16 standard bottles.

BARREL FERMENTED
Wine (usually whites) fermented in, typically, 55-gallon oak barrels rather than neutral containers such as stainless steel. Barrel fermentation requires careful cellar attention, but can contribute to increasing the complexity and flavor of a wine by adding suggestions of spice and vanilla from the interaction of the wine and the wood. Most often used in the fermentation of Chardonnay.

BIN NUMBER
The Australian equivalent of Cask Number, an unregulated phrase that can be applied to any wine (in any price range). Some wineries use a bin number to indicate their reserve, or more expensive bottlings. Other wineries use it to indicate a house style of wine, fairly consistent from year to year.

BITTER
Often caused by too much tannin, this is most often not a desirable trait in wine. However, many Italian red wines feature an appealing amount of bitterness that balances wonderfully with pasta and tomato sauces.

BLANC DE BLANCS
Wine made of white grapes, such as sparkling wines made from Chardonnay.

BLANC DE NOIRS
White wine made from red grapes, such as sparkling wines made from Pinot Noir. Blanc de Noirs often have a pale pink color.

BODY
The feeling of a wine's weight in the mouth, such as full-bodied, medium-bodied or light-bodied.

BOTRYTIS CINEREA
A fungus or mold that causes grapes to shrivel and become very concentrated. Also called the "Noble Rot," it is a desirable condition and causes ripe grapes to shrivel, resulting in the remaining juice becoming very concentrated. Such nobly rotted grapes yield the honeyed richness of many classic dessert wines like French Sauternes, German Trockenbeerenauslese, and Hungarian Tokaji. Conditions are right for the formation of Botrytis only in certain vintages and the wines cannot be produced in every year.

BOTTLE SICKNESS
A temporary condition (often caused by shaking a bottle) that interferes with a wine's fruit flavors. It can be alleviated with a few days' rest.

BOTTLED BY
Indicates the winery bottled the wine but did not necessarily grow, pick or ferment the grapes.

BOUQUET
Often used interchangeably with the word aroma. Some tasters use the term to specifically refer to the scents of a bottle-aged wine, which includes the complexities beyond the fruit aromas of a young wine.

BRILLIANT
A wine of absolute clarity. This is not important to most experienced tasters, since highly filtered wines will always be brilliant-yet the process of filtration can strip much of the flavor and character from a fine wine. Most of the finest wines available deposit sediment with aging.

BRIX
A system used to measure the sugar content of grapes and wine. On labels, wineries sometimes list the Brix at the time of harvest to express the degree of ripeness of the grapes (normally in the range of 20° to 25°). After fermentation, Brix can indicate how sweet a wine is as a measurement of residual sugar (2 degrees Brix would be slightly sweet; 10 degrees Brix residual sugar would be very sweet).

BRUT
Used by sparkling wine producers to indicate a dry wine; a producer's Brut is always drier than an Extra Dry bottling.

BULK PROCESS
See Charmat.

BUTTERY
Describes a rich wine with a texture like that of melted butter, often referring to Chardonnay.

CAPSULE
The metal or plastic material that covers the cork and top of a wine bottle. Now used for decorative purposes more than anything, capsules originally functioned as a means of protecting corks in old cellars from being attacked by insects, etc.

CASK NUMBER
An unregulated term that suggests a wine is special. Some wineries use a cask number to indicate their finest-or reserve-bottlings, such as Stag's Leap Wine Cellars and the classic Inglenook Napa wines. But cask numbers can be applied to any wine-as can the word reserve.

CHAPTALIZATION
To add sugar during the fermentation process when the grapes have not ripened adequately, for the purpose of raising the alcohol level of the wine. It is not done to make the wine sweet, as the sugar is fermented into alcohol. Chaptalization is common in northern Europe, where grapes have to struggle to fully ripen. It is legal in some regions (Burgundy) and not allowed in others (California).

CHARMAT
Also known as bulk process, this is an inexpensive way to create bubbles in sparkling wine. The wine undergoes fermentation in stainless steel tanks rather than individual bottles, and is bottled under pressure rather like pop. The result is coarser, larger bubbles and simpler flavors-but bulk process sparkling wines can be sold much more cheaply than methode champanoise wines. Popular American examples include brands such as Cooks and Andre.

CHEWY
Describes full-bodied, sometimes tannic wines-rich enough to chew on.

CLEAN
A well-made wine with no off smells or flavors.

CLONE
The offspring of grape vines that contains the genetic material of the parent. There are very many clones of grape varieties such as Chardonnay and Pinot Noir-some may ripen earlier than others, produce a larger yield, or have different charactistics the grower considers important. Research is continuing in this field and clonal selections are being studied in vineyards all over the world.

COMPLEXITY
When a wine is at once rich and deep, yet balanced and showing finesse. No greater compliment can be paid a wine. A mature Chateau Latour, d'Yquem or La Tache Burgundy are prime examples of complex wines.

CORKED
Describes a wine that smells and tastes musty or moldy; a problem caused by a defective cork.

CRUSH
The season, usually September or October in the Northern Hemisphere, when grapes are harvested and crushed.

CRUST
The name applied to sediment that forms in the bottom and sides of a wine bottle, commonly found in Vintage Ports.

CUVEE
Like the words cask and reserve, cuvee is an unregulated term that some wineries use to indicate a special (or reserve) batch of wine.

DECANTING
To slowly pour wine from the bottle into another container, thereby ridding the wine of its sediment.

DEMI-SEC
Literally "partly dry" though when referring to sparkling wines it indicates slight to medium sweetness. In sparkling wines, Demi-Sec is always sweeter than Extra Dry and Brut.

DEPTH
Describes a wine of complexity and intense flavors; a wine that makes more than a first impression and is worth paying attention to.

DRY
No discernible sugar taste.

DRYING OUT
When a wine's fruit flavor has been diminished due to age; a wine becomes less attractive and past its prime when the flavors are overtaken by the taste of tannin, acid or alcohol.

EARTHY
Can either describe a clean, complex taste and aroma that reminds one of fresh garden soil; or a funky, livestock and farm-like connotation that is not a compliment. As a positive example, earthy is often used to describe the wonderful flavor of red Graves wines such as Chateau Haut Brion.

ELEGANT
Describes beautiful, well-balanced wines-graceful, not necessarily full-bodied.

ENOLOGY
The science of winemaking; also spelled oenology.

ENOPHILE
Someone who enjoys and appreciates fine wine; also spelled oenophile.

ESTATE-BOTTLED
Indicates a winery owns the vineyard from whence the grapes come or has a long-term lease arrangement for the grapes.

EXTRA-DRY
The equivalent of semi-dry, Extra Dry is a term used to describe sparkling wines that are not as dry as Brut.

EXTRACT
Pronounced concentration of fruit in a wine. A good sign unless it is manifested in too-high levels of tannin.The components and concentration of a wine that contribute to its flavor. Over-extracted wines, however, are often harsh due to fermenting too long on the grape skins.

FAT
Describes the feel of wines that are full-bodied and mouth filling. Most late-harvest dessert wines, for example, are luscious and fat.

FERMENTATION
When sugar is turned to alcohol by yeast, causing grape juice to become wine.

FIELD BLEND
It used to be a common practice to intersperse complementary grapevines in a vineyard; when all the grapes are harvested together, the resulting wine is often referred to as a field blend. Examples include many of the old Sonoma Zinfandel vineyards (such as Ridge Lytton Springs) where Petite Sirah was commonly planted with Zinfandel.

FILTERING
A process of "cleaning up" a wine used after fermentation (and before bottling); similar to running coffee through a filter, but arguably not always necessary to produce fine wine. The purpose of filtering is to remove sediment, grape skins, dead yeast, etc., from the wine. Filtering can range from very fine to coarse; however, it is increasingly being minimized (or avoided whenever possible) because the finer the filtering, the more flavors and character are stripped from the wine. Many wineries are using the more labor-intensive, old-fashioned practices of fining or racking to clarify wines these days. Historically, many filters before the 1980's were made from asbestos.

FINING
A traditional winemaker technique for clarifying wines by adding egg whites or bentonite (clay) to casks of wine; the eggs collect particles and sediment and slowly sink to the bottom of the cask (where the material is then removed). Considered a less intrusive process for clarifying wines than filtering.

FINISH
The lasting impression, or aftertaste, of a wine on the palate. A long, complex finish is desirable.

FLABBY
Soft feel and lack of acidity on the palate; the opposite of firmly structured wines.

FLAT
Often used to describe wines that are low in acidity and lack zip.

FLESHY
Soft, smooth texture with low tannins.

FLINTY
A stone or mineral-like character often used to describe Sauvignon Blanc and French Chablis.

FLORAL
Tasting and/or smelling of flowers

FORTIFIED
Wines with a higher than normal alcohol content due to the addition of brandy or spirits. Examples include Port, Sherry and Madeira.

FRENCH OAK
The classic wood for wine barrels, it imparts flavors of vanilla, cedar and/or other spices. The oak from different French forests lends slightly different characteristics to the wine, and is therefore named for the forest region from which it was harvested. Famous French names include Limousin, Nevers, Allier and Troncais. French oak is vital not only in the production of great French wines, but is also used around the world to age everything from California Chardonnay to Oregon Pinot Noir to Australian Cabernets.

FRUIT BOMB
An informal wine term often applied to New World (especially California) wines produced from very ripe grapes that emphasize lush fruit flavors combined with soft, low acid structures. Examples of fruit bombs include the soft, tropical-fruit-like Chardonnays of Kendall-Jackson.