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.
Volatile Acidity (VA) : An excessive and undesirable amount of acidity, which gives a wine a slightly sour, vinegary edge. At very low levels (0.1 percent), it is largely undetectable; at higher levels it is considered a major defect.
Acetic Acid: All wines contain acetic acid, the active ingredient in 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.
Aggressive: Unpleasantly harsh in taste or texture, usually due to a high level of tannin or acid.
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.
Backbone: Describes the structure of a wine, referring to balanced acidity, alcohol and, in red wines, tannin. Wines lacking structure are thin or flabby.
Balance: A wine is balanced when its elements are harmonious and no single element dominates. The "hard" components—acidity and tannins—balance the "soft" components—sweetness, fruit and alcohol.
Bite: A marked degree of acidity or tannins. An acid grip on the finish should be more like a zestful tang, and is in general prized only in richer, fuller-bodied wines.
Body: The impression of weight, fullness or thickness on the palate; usually the result of a combination of alcohol, sugar, dissolved solids (including sugars, phenolics, minerals and acids) and, to a lesser extent, glycerin. Common descriptors include light-bodied, medium-bodied and full-bodied. For example, skim milk could be considered "light-bodied," whole milk "medium-bodied" and cream "full-bodied." Although a fuller-bodied wine makes a bigger impression in the mouth, it is not necessarily higher in quality than a lighter-bodied wine.
Cloying: Describes ultra-sweet or sugary wines that lack the balance provided by acid, alcohol, bitterness or intense flavor.
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.
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.
Fat: Full-bodied, high alcohol wines low in acidity give a "fat" impression on the palate. Can be a plus with bold, ripe, rich flavors; can also suggest the wine's structure is suspect.
Flabby: Describes a wine that is unbalanced due to insufficient acidity, lacking backbone.
Flat: Describes a wine that is dull in flavor and unbalanced due to insufficient acidity. Can also refer to a sparkling wine that has lost its bubbles.
Hard: Firm; a quality that usually results from high acidity or tannins. Often a descriptor for young red wines.
Lees: Sediment—dead yeast cells, grapeseeds, stems, pulp and tartrates (harmless tartaric acid crystals)—remaining in a barrel or tank during and after fermentation. Immediately following fermentation, wine should be racked off of the gross lees, the large particulate matter such as seeds, skins and stems, which are rich in spoilage organisms. The wine may be aged for an extended period on the fine lees, however, in what's called "sur lie" aging. Fine lees, the dead yeast cells leftover from fermentation, can enhance an aging wine with added richness, flavor and aroma complexity, and can also bind with excess tannins.
Malic Acid: A sharp, tart acid found in grapes as well as in green apples. Less-ripe grapes or grapes grown in cooler climates can contain high levels of malic acid; the resulting wines often contain aromas and flavors reminiscent of green apples. It is converted to smoother lactic acid during malolactic fermentation.
Malolactic Fermentation (ML): A bacterial conversion occurring in most wines, this natural process converts sharper malic acid (found in green apples) into softer lactic acid (found in milk). Total acidity is reduced; the wines become softer, rounder and more complex. In addition, malolactic fermentation stabilizes wines by preventing an undesirable fermentation in the bottle. Often called the secondary fermentation. Frequently associated with big, rich, buttery Chardonnay, malolactic fermentation is prevented when fresher, crisper styles are desired.
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.
Pungent: Having a powerful, assertive smell linked to a high level of volatile acidity.
Raw: Young and undeveloped. A good descriptor of barrel samples of red wine. Raw wines are often tannic and high in alcohol or acidity.
Soft: Describes wines low in acid or tannin (sometimes both), making for easy drinking. Opposite of hard.
Structure: Related to the mouthfeel of a wine, provided by acidity, tannin, alcohol, sugar and the way these components are balanced. Wines with low, unbalanced levels of acidity or tannin can be described as "lacking in structure" or "flabby." When the acidity or tannin levels are sufficiently high, a "firm structure" is the result.
Tart: Sharp-tasting because of acidity. Occasionally used as a synonym for acidic.
Tartaric Acid: The principal acid in grapes and wine; contributes to taste and stabilizes color. Unlike malic acid, tartaric acid does not decline as grapes ripen. Tartaric acid can precipitate out of solution in bottled wine to form harmless tartrate crystals resembling shards of glass.
Tartrates: Harmless crystals resembling shards of glass that may form during fermentation or bottle aging (often on the cork) as tartaric acid naturally present in wine precipitates out of solution. Components of tartaric acid, including potassium bitartrate and cream of tartar, are less soluble in alcoholic solutions than in grape juice and solidify at cooler temperatures (such as those found in a refrigerator); can be avoided in finished wines through cold stabilization. Decanting and careful pouring can prevent transferring the crystals from the bottle into the glass.
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.
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.
Blending: Wines are blended for many reasons. To make a more harmonious or complex wine, wines with complementary attributes may be blended. For example, a wine with low acidity may be blended with a high-acid wine or a wine with earthy flavors may be blended with a fruity wine. To create a uniform wine from many small batches is another goal, since grapes from different vineyards, stages of the harvest and pressings are frequently vinified separately and the small batches differ slightly. Red Bordeaux offers a prime example; five different grapes may be used, each contributing its own nuances to the blend.
Crisp: Describes a wine with moderately high acidity; refreshing and bright with a clean finish.
Disjointed: Describes wine with components that are not well-knit, harmonious or balanced. The timing of the components may be off; upon tasting, a disjointed wine might first reveal big fruit, followed by a blast of screeching acidity and finishing off with a dose of tannins.
Eiswein: Wine made from grapes that have frozen on the vine. Since only the water in the grapes freezes, the super-concentrated grape pulp produces a wine that is very sweet and often high in acidity. Eiswein is an official German classification; such wines from other regions are called ice wine.
Kabinett: German classification based on the ripeness level and sugar content of the grapes. At the entry level of Prädikatswein, the highest group of quality German wines, kabinette are usually low in alcohol, with crisp acidity. The wines can be dry, halbtrocken (half-dry) or sweet.
Lactic Acid: A smooth (not sharp) acid created during malolactic fermentation. This acid is also found in milk.
Mouthfeel: Describes the sensation of wine in the mouth. Most descriptors are related to texture, for example: silky, smooth, velvety and rough. Mouthfeel is influenced by wine components, as acidity can be sharp, alcohol can be hot, tannins can be rough and sugar can be thick or cloying.
Racy: A tasting term referring to a style, rather than a smell or taste, generally marked by lively acidity and light juiciness.
Ripe: The stage at which the grapes' many components have reached maturity. As a grape ripens, sugar content increases and acidity decreases. Flavor compounds develop and the stems turn from green to brown, indicating that the tannins in the stems, seeds and skins are softening.
Autolysis: A chemical reaction between the wine and the lees by which enzymes break down the dead yeast cells, producing amino acids and releasing proteins and carbohydrates into the wine. It imparts characteristics in a wine such as richness and creaminess as well as aromas of bread dough, toast or brioche. It is a key element of the traditional method of making sparkling wine, such as Champagne.