Glossary of Winemaking Terminology

Aging: The storing of wine to allow it to mature.

Airlock: A device that allows gas to escape from a vessel containing wine, but allows no air to enter.

Aroma: The smell of the grape variety us d in a given wine. If there is no varietal smell but there is a grapes smell, the aroma is termed vinous.

Berry: An individual grape.

Blending: Mixing two or more wines together for adjustment of flavor, acid, or aromas in the finished wine.

Body: A certain fullness of feel in the mouth imparted by a well-made wine; a full structure in the taste of a wine.

Botrytis: A mold that attacks grapes.  Under special climactic conditions, it can concentrate the flavors and sugars and produce a superior wine.

Bouquet: The smells in wine that develop in the bottle and are especially detectable when a wine is well aged.

Brix: A measure of the percentage of sugar in the grape juice or must.

Cap: Residue of skins and grape particles that float on the must during primary fermentation.

Capsule (PVC Caps): A foil or plastic covering for the top of a wine bottle.

Carboy: Large bottles, such as used for bottled-water coolers. Used extensively in the home winemaking process.

Chaptalizing: Adding sugar to crushed grapes of deficient natural sugar. A common, and often necessary process when making country (fruit based) wines.

Cold Stabilization: Chilling wine to approximately 30*F (-1*C) so that potassium bitartrate crystals precipitate out.

Crushing: Crushing or smashing fresh grapes to a pulp to release the juice prior to fermentation.

Cultivar: Horticultural shorthand for "cultivated variety." Same meaning as Variety; i.e., a kind of grape vine, such as Cabernet Sauvignon.

Dry Wine: A wine in which almost all the sugar, or all of the sugar, has been fermented to alcohol.  Any wine with less than a half percent sugar.

Enology: The science of winemaking.

Extended Maceration: The practice of delaying the pressing of red wine to increase extraction of flavor and color components.

Filtering: Running wine through a filter to remove sediment or yeast.

Fining: The process of adding a substance to wine to clear it of cloudiness.

Herbaceousness: In wine tasting, a vegetable taste. In grape growing, herbaceous growth is green and succulent.

Hydrometer: An instrument for measuring the specific gravity of a liquid.

Lees: Sediment in the fermenting or finished wine.

Legs: Rills of wine that form on the sides of a wine glass.

Malolactic Fermentation (MLF): A beneficial fermentation in wine caused by Leuconostoc bacteria.  It changes malic acid to lactic acid, softening the taste.  It may happen naturally, but is usually induced by the winemaker.

Must: A mixture of crushed grapes, juice, stems, and skins.  The term refers to this mixture from the time the grapes are crushed until the mixture is pressed.

Oaking: Adding oak flavors to wine by aging the wine in an oak barrel or soaking barrel substitutes (oak chips, cubes, staves, or spirals) in the wine.

Oxidation: The combination of air with components of fresh juice or wine. Some oxidation is desirable in the early part of fermentation, but oxidation is not desirable at all later in the process, as it causes browning and reduces wine quality.

pH: A measure of the intensity of acidity in a liquid, such as wine.  It measures the concentration of hydrogen ions.

Pomace: the solid waste left after the juice is pressed out of the must.

Pressing: Squeezing the juice from must with a grape press.

Primary Fermentation: The initial, rapid fermentation during which two-thirds of the sugar in the must is convertated by yeast to alcohol.

Punching Down: Mixing the cap on a must down into the juice or fermenting wine. Done at least twice a day during the primary fermentation.

Racking: Siphoning wine from one container to another to separate wine from the lees.

Residual Sugar: Sugar left in a wine after fermentation is finished.

Retronasal Aroma: The smells of a wine that are detected when they enter the nasal cavity from the back; that is, they waft into the nose from behind the palate.

Rim: The thin edge of wine in a tilted glass.  The rim color is a measure of quality.

Secondary Fermentation: The slower fermentation, accomplished away from air, that reduces the sugar left after primary fermentation to alcohol.

Stemmed-crusher: A machine that removes stems from clusters of grapes and crushes the grapes to make must.

Stemming: Removing stems from clusters of grapes before or after crushing.

Sticking (Stuck Fermentation): A stoppage of fermentation before sugar is entirely converted to alcohol, usually due to yeast dying off from lack of nutrients or to chilling.  Stuck fermentations can often be restarted.

Sulfiting: Adding potassium or sodium metabisulfite to a must to kill or stun unwanted yeast.  Wine yeasts are tolerant of the amount of sulfite added to a must.

Tannin: A bitter substance contained primarily in grape stems.  Tannin preserves long-lived wines, eventually decomposing when the wine reaches maturity.

Teinturier: A grape variety used in blending to add color to a finished wine.

Titratable Acidity: A measurement of the amount of total acid in a must or wine, expressed as its tartaric acid content.

Topping Up: Adding a second and similar wine to a vessel to fill it up, when the wine you have doesn't reach the top.

Variety (Varietal): Same as a Cultivar.

Vinify: To ferment; i.e., to change a solution of sugar with yeast. The yeast then converts the sugar to alcohol and carbon dioxide gas.

Vintage: There are several meanings. Vintage refers to the crop of any given year.  It is sometimes used to refer to the crops of years of exceptionally fine quality, such as with Vintage Port or Vintage Champagne. Also refers to the harvest of grapes from a  vineyard.

Viticulture: The science of growing grapes.

Yeast: One-celled plants that grow naturally on grape skins and convert sugar to alcohol.  Yeast is the catalyst that changes grape juice to wine.  Special strains of yeast are used in fine winemaking, and are available commercially.