A

There are a variety of acids in a wine. The principal ones are Acetic Acid, Malic Acid, Tartaric Acid, Lactic Acid, Citric Acid, and Carbonic Acid.

A wine’s acidity should be detected through the sharpness felt after tasting, particularly on the tip of the tongue. It should neither be too obvious nor completely absent. The acidity helps create a refreshing sensation in white wines and balance in reds. Its absence makes a wine dull and ‘flabby’ – an undesirable defect for any wine, but particularly in sweet wines. Sweet wines become undrinkable without balancing acidity. Even too much acidity can make a wine difficult to drink.

The taste is left on the palate after the wine has been swallowed. The persistence of the aftertaste—the length—may indicate the quality of the wine.

Many different compounds are described as ‘alcohol.’ Here, we are referring to ethyl alcohol, the product of yeast's alcoholic fermentation of sugar. Its presence is measured in percent volume (or “proof”).

The action of yeast upon sugar converts to ethyl alcohol, with carbon dioxide as a by-product. Fermentation often starts naturally with yeasts on the grapes, but cultured yeasts may be added. The process generates much heat, and temperature control during alcoholic fermentation can significantly affect the style of wine produced. The process will cease either when all the sugar has been consumed or, more likely, when the increasing alcohol content of the fermenting solution kills the yeast or when the external temperature drops too low. It may also be arrested by adding sulfur or by fortification with spirit.

A French word that describes an alcoholic beverage served before dinner to stimulate appetite.​

Defines the area where a wine’s grapes are grown.​

Often abbreviated to AC or AOC, this is the highest legal classification for French wine, above Vin Délimité de Qualité Supérieure, Vin de Pays, and Vin de Table. To qualify for the AC, wines must be produced from grapes grown within a geographically defined area and conform to regulations concerning grape varieties, yields, alcohol content, and so on. Although AC means these features are guaranteed, it is not a quality guarantee.

The simple, fruity smell of the grape variety is used in the wine.​

A term used to describe a wine that is unforthcoming – often they are young, tannic wines. They give little pleasure at the time, but it is likely that they will improve with age.