Wine production

Glossary

T

TABLE WINES. Grape wines that are made by a single, complete fermentation. They are therefore limited to about 12 percent alcohol (under 14% by U.S. tax category) unless made from botrytized musts or dried grapes.

TANNINS. A loose term encompassing polyphenols that bind and precipitate protein. Present in grape skins, stalks and seeds (condensed tannins) and also oak products (hydrolyzable tannins). Tannins are an important component of a wine's structure and texture, and act as a natural preservative that help wine age and develop.

TARTARIC ACID. The most abundant acid in grape juice. The strongest of the acids of wine.

TARTRATES. Crystal deposits of either potassium bitartrate or calcium tartrate that may form during the maturation or storage period. Potassium bitartrate is naturally present in all wine; most is removed before bottling, but some may linger in the form of harmless tartrate crystals.

TASTE. Taste is restricted to those sensations that require placing the wine in the mouth.

TAWNY. The brick-red color which develops as red wine ages usually with some oxidation, as opposed to bright red or blue-red. A defect in wines intended to be fresh and fruity like most roses, but expected and often a mark of quality in mature red wines. It indicates a special style in ports, and, if produced by heating the wine, is not necessarily viewed as a quality improvement.

TCA (2,4,6-Trichloroanisole). A chemical compound that can give wine a musty, dirty, bitter, chalky character often described as moldy newspapers or damp cardboard.

TERPENE. A class of unsaturated hydrocarbons responsible for certain aromas that are characteristic of a grape variety such as the petrol notes of mature Riesling or the floral aroma of Muscats.

TERROIR. A French term bringing together the notion of soil, microclimate, landscape and environment within a particular vineyard site and the result ant effect on the vines.

TITRATABLE ACIDITY. Titratable acidity is that determined by quantitative titration with alkali. Usually, it is expressed in grams of tartaric acid per liter in wines. Volatile acidity, as acetic acid, is very low in wines unless activity of vinegar bacteria has been appreciable. (See also pH.)

TITRATION. The process of the determination of the concentration of a dissolved substance by the addition of measured quantities of a suitable reactant.

TOAST. The charring of the wine staves during cask manufacture or rejuvenation.

TOPPING. Adding more wine to barrels to remove "head space." During the aging process, wine kept in oak barrels or other semi-permeable vessels evaporates over time, creating what is called head space. While a small amount of oxygen can be beneficial, too much can result in oxidation and lead to various wine faults. Topping the barrels minimizes the oxygen in contact with the wine.