Aging

Wines that are stored properly can undergo a number of transformations. In red wines, ideally, the color can change from a rich purple to a lighter old-velvet red and the flavors can soften and lengthen. The primary chemical change has to do with tannins. Tannins are part of the phenolic family and as wine ages, molecules of these phenolics link together forming longer and longer chains. Eventually, these large molecules fall out of the liquid and form part of what is called the sediment. Since tannins can be responsible for an astringent quality to red wines, as they fall out of the liquid, the flavor can soften, leaving behind the more majestic characteristics of the fruit. In many white wines, which do not begin their lives with a high tannin content, the primary changes are a browner color and the flavor takes on stronger characteristics often described as as carmelization.

Appellations

A geographically-based name for a winegrowing region that is believed to show unique characteristics of soil, climate and more. In the United States, appellation names such as Napa Valley are approved by the Bureau of Alcohol, Tobacco and Firearms. The term "sub-appellation" is used informally to refer to a smaller appellation wholly contained within a larger one.

BudBreak

The stage of the growing season, usually early spring in the Napa Valley, when tiny shoots emerge from their buds.

Clone

In viticulture, a clone refers to a vine variety that is selected for specific qualities which result from natural mutations. Cuttings are made from an original "mother vine" that exhibits key characteristics, such as resistance to certain diseases or desired cluster size, taste, smell, etc. Mother vines are often grown at a university and cuttings are supplied to nurseries who in turn sell them to grape growers. Clones such as these come with a registered historical background.

Corked

Wine that is "corked" has been contaminated by its cork stopper and takes on an unpleasant moldly aroma and flavor sometimes described as "wet newspaper."

Crush

A term for the time of year when Napa Valley is harvesting and crushing its fruit. Crush specifically refers to putting newly picked grapes into a "de-stemmer," a machine that de-stems the fruit and crushes it, releasing juice from the berry.

Enology

The study and science of winemaking.

Fermentation

A chemical process in which yeast consumes the sugar in juice, converting it into alcohol and carbon dioxide. In red and white wine production, the carbon dioxide is released during fermentation, while in sparkling wine, the carbon dioxide is trapped, producing bubbles.

Grafting

The process of physically connecting two plants or pieces of plant tissue together to grow as one. In viticulture, grafting is often used to join a rootstock with a vine variety.

Maceration

After grapes are crushed, maceration is the period in which the juice spends time in direct contact with the skins and seeds in a steeping process that will transfer important characteristics to the finished wine. Microclimate - A small area with climatic conditions significantly different than the region at large.

Phylloxera

A small aphid that feeds on and fatally damages vine root systems.

Pierce's Disease

A fatal disease caused by a bacteria borne by the blue-green sharpshooter or glassy-winged sharpshooter, a leafhopper insect. The bacteria transmitted by the sharpshooter multiply and eventually block the vine's water-conducting systems.

Rootstock

The root system to which a vine variety is grafted.

Sparkling Wine

This bubbly wine is traditionally made from pinot noir, chardonnay and pinot munier. When made in the Champagne region of France, it's called Champagne.

Tannins

A group of chemicals that naturally exist in the skin and seeds of grapes (and many other plants) and give finished wine varying degrees of astringency. For a household example of how tannins can affect the palate, try oversteeped tea.

Trellis System

The supporting framework on which a vine is trained to grow.

Veraison

The stage of the growing season when young green grapes soften and either turn yellow or red in color depending on the variety. In Napa Valley veraison can occur from late June through mid-August, depending on the year.

Variety

A particular type of grape, such as Chardonnay, Cabernet, Merlot, etc.

Varietal

A wine made from a single grape source, such as Chardonnay, Cabernet, Merlot, etc.

Vintner

A person who produces wine.

Viticulture

The study and practice of growing grapes.

Wineries have always used wine labels to provide customers with useful information to assist them in the selection and appreciation of wine. Beginning January 1, 1983, new federal wine label requirements changed the minimum information that a label must contain and also redefined the meaning of particular terms.

Napa Valley wineries have historically provided a good deal more information than the minimum amount required by law and have spent millions of dollars and years in the courts defending consumers, and the Napa reputation, with truth in labeling laws.

Brand Name

Mandatory. If no brand name is on the label, the bottler's name is considered the brand. It is also useful to refer to the bottler's name if a winery has several brands.

Vintage

Optional. The year designates the year in which the grapes were harvested. As of May 2006, the U.S. law allows up to 15% of the blend can be from a vintage other than the stated year. The law was designed to allow American producers to be held to the same standards as other wine producing countries, previously the U.S. standard required 95% of the stated vintage be in the bottle. This regulations only applies to wines that do not use American Viticultural Area (AVA) designations as appellation of origin. For example, if the grape source is noted to be "California," the 85% of stated vintage rule is applicable. Appellation-specific wines are held to a higher standard. For wines noted to be from a specific AVA, for example, Napa Valley or one of its sub-appellations, the rule is 95% of the grapes must be from the stated vintage. The vintage bears no relationship to when the wine was bottled.

Appellation of Origin

Wine labels may contain several levels of geographic distinctions:

• California State law requires that 100% of the grapes come from within California.
• Other States Federal law and nearly all other states require that 75% of the fruit must come from within the named state.
• Officially Designated Viticultural Areas. Since 1983, at least 85% of the grapes must come from the named region (for example "Napa Valley.")

Wine Type

Mandatory. A wine may be labeled by a grape or varietal name such as Chardonnay or Cabernet Sauvignon, or it may be given a generic name such as "Red Table Wine." Prior to 1983, a wine labeled as a varietal was required to contain at least 51% of the named grape varietal and have the "taste, aroma, and characteristics" of the grape varietal. Beginning in 1983, wines using varietal names must derive at least 75% of their volume from the grape designated.

Special Designations

Optional. Labels often contain special terms to indicate unusual qualities of the wine, such as degree of sweetness or color. Sometimes the wine was of such a high standard as to be designated by the winemaker as a special selection or private reserve.

Vineyard of Origin

Optional. Many wineries name the vineyard in which the grapes were grown because the winery believes the property produces an unusually high-quality grape. The winery or an independent grower may own the vineyard. Federal policy requires that 95% of the grapes must have been grown in the vineyard named.

Producer and Bottler

Mandatory. This part of the label gives a great deal of information about the production of the wine. The label must indicate the bottler and its location. Several descriptions are common:

• "Produced and bottled by" certifies that the bottler fermented 75% or more of the wine. Used in combination with other information on the label, such as a vineyard, this term provides the consumer with significant information about the origin of the wine and who is responsible for its production.
• "Cellared and bottled by" indicates that the bottler has aged the wine or subjected it to cellar treatment before bottling.
• "Made and bottled by" indicates that the bottler fermented at least 75% of the wine (10% before July 28, 1994).
• "Bottled by" indicates that the winery bottled the wine, which may have been grown, crushed, fermented, finished, and aged by someone else.

Estate Bottled

Optional. This term certifies legally that the winery grew 100% of the grapes on land it owns or controls and that the winery crushed, fermented, finished, aged, and bottled the wine in a continuous process. Both the vineyard and winery must be located in the viticultural area that is stated on the label.

Alcohol Content

Mandatory. This statement on a table wine indicates the alcohol content by volume, with a tolerance of plus or minus 1.5%. However, the tolerance cannot be used to label as a table wine a wine containing more than 14% alcohol. Dessert wines contain more than 14% but no more than 21% alcohol and are permitted a plus or minus margin of 1%.

Net Contents

Mandatory. The fluid volume in metric measurement must be indicated on the label or be blown into the glass.

Declaration of Sulfites

Mandatory. Beginning in 1988, wines which have a level of 10 parts per million or greater of sulfur dioxide must be labeled with a sulfite declaration.

Government Warning

Mandatory. All wine bottled after November 18, 1989 must bear the federal warning.