Glossary of Wine Terms

Glossary of Wine Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

 A -

 

Acetic: Acetic acid is the acid that gives vinegar its characteristic taste. Small amounts of acetic acid, about 0.5 grams/liter, are normal in wine; amounts over 1.0 gram/liter give wine a vinegar-like character.

Acidity: The natural crispness of a wine. Grapes have two primary acids: tartic and malic, Citric, lactic and succinic acids are usually also present in small amounts in grapes.
 

Aging Sur Lie: Translated “aging on the lees” and often referred to as “yeast contact”. Wine is aged in the barrel with the yeast retained, rather than being clarified before aging. Aging on the lees increases the complexity and creaminess of the wine.
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- B-

 

Barrel Aging: The process of holding wine in oak containers to allow flavor and aromatic compounds to mature and change beneficially.

Barrel Character: The flavor and aromatic compounds an oak barrel contributes to the wine. Barrel character varies by the origin or forest of the wood, coopering techniques including toasting and length of oak aging, and the age of the barrel.

Barrel Fermentation: The conversion of grape juice into wine by yeast in a 60-gallon French oak barrel. Barrel fermentation gives Chardonnay and Sauvignon Blanc more complexity and integrated oak flavor.

Bloom: Flowering of the grapevines. Bloom is also a waxy substance found on the skins of grapes.

Brix: The measurement of soluble solids in grapes at harvest, taken with a refractometer and expressed in degrees. In unfermented grapes, degrees of Brix are approximately the same as percent of sugar. During fermentation, about half the sugar becomes alcohol, with the balance going to carbon dioxide. Thus, grapes harvested at 22.5 degrees Brix will produce a wine with an alcohol content between 12.5 to 13.5%.

Bud: A small protuberance on a stem or branch, often enclosed in protective scales and containing an undeveloped shoots, leaves or flowers.

Bud Break: When the first shoots emerge on a vine after winter dormancy.

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Cane: The previous season's shoots that have matured and become woody. Selected canes are retained during pruning for the following season's fruit production.

Canopy: The leaves and shoots of grapevines.

 

Cap: Carbon dioxide produced by the yeast during fermentation of red wines carries the grape skins to the top of the fermenter, forming a cover or cap.

Clone: The propagation of a group of plants from a single source to perpetuate selected characteristics or special characteristics; the variety so produced.

Cold Stabilization: A technique of chilling wines before bottling to cause the precipitation of harmless tartrate crystals.

Complexity: The term used when a wine has multiple flavor and aroma characteristics from the vineyard source, winemaking techniques and/or bottle development.

Corky: An ”off” characteristic in wines due to imperfect corks. Caused by the chemical compound trichloroanisole or TCA, corkiness is believed to come from fungi that are not detectable on dry corks, or by a cork processed with chlorine. TCA diminishes the fruit character of  the wine, substituting a character like moldy newspapers or old swimming pool towels.

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Diatomaceous Earth: A light, brittle material derived from fossilized microscopic unicellular algae called diatoms, used as a filter in clarifying wine.

 

Direct-To-Press: Pressing grapes as whole clusters rather than destemming first. The preferred method for pressing Chardonnay, Sauvignon Blanc and sparkling wine grapes because the stems act as a pressing agent so less force is needed, and there is less tannic pick-up in the wine.

 

Dry: The absence of a sweet taste sensation.

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 - E -

 

Elemental Sulfur: A chemical used to dust vineyards as a control for powdery mildew.

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Fermentation: The conversion of sugar to alcohol, carbon dioxide and heat by yeast.

 

Filtration: Passage of wine through cellulose pads, diatomaceous earth or membranes to remove suspended solids, yeast or malolactic bacteria. Sweet wines must be filtered to remove yeast and prevent re-fermentation in the bottle.

 

Fining: The traditional method of clarifying wine. Insoluble substances bind with wine components and precipitate to reduce tannin or remove unstable proteins.

 

Fruiting Wire: The wire closest to the fruiting zone of the vine.

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Graft: To splice a varietal vine to the rootstock of another type, usually one resistant to particular pests or diseases.

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Hermaphrodite: Self-pollinating plants containing both male stamens and female ovary.

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Inoculation: The introduction of a special yeast culture, or any other organism, into the pressed grape juice.

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- L -

 

Lees: Sediment occurring during winemaking or bottle aging.

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- M -

 

Malolactic Fermentation: The bacterial conversion of the crisper, apple-type malic acid to the softer, milk-type lactic acid in wine. Also called ML or secondary fermentation, this acid conversion yields wines with increased complexity and softer acidity.

 

Must: The skins, seeds and juice of crushed berries; may also contain whole berries or whole clusters. Red wines are fermented as must; white wines are pressed and fermented as juice.

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- N -

 

Native Malolactic Bacteria: Bacteria occurring naturally on grape skins.

 

Native Yeast: Yeast occurring naturally on grape skins.

 

Natural Farming: The use of agricultural techniques with the least impact on the natural balance of the environment.

Nematodes: Insects that live in the soil and attach to vine roots in their larval form. Nematodes can stunt the growth of vines, and transmit viral diseases.

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- P -

 

Phenols: A family of compounds, including color and tannin, found in grapes.

 

Phylloxera: A tiny louse that attacks the root system of vines, responsible for killing over three million acres of vines in Europe in the 1800s. Grafting to resistant rootstock is the only known way to combat this pest.

 

Post-Fermentation Maceration: Skin contact with red wines following fermentation. Also called ”extended skin contact”, the process extracts flavor compounds, color and tannin resulting in greater varietal character and more developed tannins.

 

Powdery Mildew: One of several fungi that can cause severe damage to grape crops; also called oidium.

 

Pruning: Cutting back the vegetative part of the vine after it has become dormant. Pruning affects the size and quality of the next year's crop.

 

Pump-Overs: The pumping of fermenting red wine over the cap of skins to extract more flavor, color and tannin from the skins. In “punch-down” or remontage, the cap is submerged repeatedly into the must by pushing down the skins manually.

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- R -

 

Racking: The gravity-siphoning or gentle pumping of the clear wine or juice off the lees for clarifying. Often used as a gentler alternative to filtration, and to aid in the wine's barrel development.

 

Roto-Tanks: Horizontal tanks used to separate juice from skins on crushed white grapes prior to pressing. Located above the Bucher presses in the cellar, roto-tanks can also be used to ferment Cabernet Sauvignon late in harvest. Tanks can be rotated periodically to mix the cap into the juice.

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- S -

 

Scion: A cutting used in grafting, containing a bud of the desired vine.

 

Second Crop: Fruit that matures after the first crop has been picked; the clusters are usually smaller and the shoots weaker.

 

Shoot: The current season's stem growth that bears leaves and buds.

 

Sound: Grapes that are free of molds or mildews.

 

Stable: When wine is in a state in which it does not develop negative characteristics in the bottle, such as re-fermentation, premature browning or protein haze.

 

Sulfites: Sulfur-based compounds used to protect wine from oxidation and bacterial activity.

 

Sulfur Dioxide: Traditionally used to protect wine from oxidation and microbial activity during aging. Wines that undergo post-alcoholic fermentation in the bottle do not need sulfur dioxide until much later in barrel aging because carbon dioxide produced by malolactic bacteria blankets and protects the wine.

 

Sur Lie: Translated “aging on the lees”, and often referred to as ”yeast contact.”; Wine is aged in the barrel with the yeast retained, rather than being clarified before aging. Aging on the lees increases the complexity and creaminess of the wine.

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- T -

 

Tannins: The group of astringent and bitter compounds found in the seeds and skins of grapes which slow oxidation and promote aging.

 

Tartrate Crystals: Tartaric acid, the primary acid in grapes, forms tiny crystals when chilled. These crystals adhere to the cork or form sediment in the bottle, and are not considered a defect.

 

Toasting: The flame heat used to bend the staves of the oak barrel toasts the wood, and this impacts the flavor and aromatic characteristics of the wine during barrel aging.

 

Topping: During barrel aging, some water and alcohol evaporate, concentrating the wine slightly and creating an airspace in the barrel. To prevent the harmful effects of oxygen contact with the wine, the barrel is topped-up periodically with the same wine from another container.

Trellis: The wires and stakes that support the vine.

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- U -

Unfiltered: Wine that has not gone through a filtering process to clarify it.

 

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- V -

Varietal Character: The character typical of a specific grape variety.

Veraison: The stage when grapes begin to soften and gain color.

Viticulture: The study of grape growing.

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Whole Berry or Whole Cluster Fermentation: Techniques that increase the fruitiness and tannin of whole berries or clusters.

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Yeast Autolysis: The breakdown of yeast during aging on the lees, in which compounds are released that heighten the sensory qualities of the wine and increase its complexity.

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