Acid—A natural component of the grape, primarily tartaric acid. Acid adds flavor and crispness, and its tartness provides "backbone" to the wine.
Aging—Leaving the wine alone in a barrel or bottle for a period of weeks, months or years. This allows the wine to mature, and the flavors and other components to blend and harmonize.
Alambic—The pot, traditionally copper, which is used for distilling spirits such as brandy.
Alcohol—Ethyl alcohol. During fermentation, yeast breaks down the sugars in grapes and turns it into alcohol. Before fermentation, it's grape juice. Afterwards, it's wine. Napa Valley wine generally has anywhere from 10 to 14 percent alcohol. (Once a fermenting wine gets up to around 16 percent, which is possible if it started with very high sugar levels, the yeast dies and fermentation stops.)
Aperitif—A wine served before a meal.
Appellation—A particular wine-growing region that has been designated by the Bureau of Alcohol, Tobacco and Firearms as having shared characteristics of climate, soil or other conditions.
Aroma—The smell of a wine, particularly from the natural characteristics of the grape itself.
Astringent—Producing a puckering sensation in your mouth, such as you would experience when drinking tea. Comes primarily from tannins in the wine, which are found in grape skins, seeds and stems. Oak barrels also add tannins to the wine.
AVA—An "American Viticultural Area"; a more specific area than an "Appellation". Wines that have an AVA on the label must have at least 75 percent of the wine from that area.
Backbone—The acid in a wine. A wine that has insufficient acidity "lacks backbone".
Balance—When a wine is well-balanced, all its components—fruit, acid, alcohol, tannins, body—are in harmony, with no one component dominating the others.
Barrel—A wooden barrel, holding 55—60 gallons, used for aging, and sometimes fermenting, wine. Usually made of French or American oak.
Barrel Aging—Many wines are aged for a period of time in oak barrels, which allows a blending of the flavors in the wine as it matures, and also imparts the flavor of the toasted wood to the wine.
Barrel Fermentation—Converting grape juice to wine in a barrel rather than in a stainless steel fermentation tank. This imparts flavors and aromas to the wine from the oak wood. Often used for Chardonnay.
Black Grapes—The grapes used to make red wine are actually almost black in color. Examples are Cabernet Sauvignon and Merlot.
Blend—To mix together several lots of wine (perhaps from different vineyards and/or years, or even different varietals) in order to produce a desired wine.
Body—The "weight" of the wine, usually light, medium or full. A wine with a higher alcohol content and heavy tannins is felt to be full-bodied. Usually a fuller-bodied wine also has bigger "legs". Body is also a result of viscosity, which can be increased with higher residual sugar.
Botrytis—A fungus that can form on the skins of late harvested grapes, producing "bunch rot". It can ruin a crop or, under just right conditions, it can produce smaller grapes with intense flavors and high sugar content. Known then as the "noble rot", it results in highly-prized dessert wines.
Bottle Aging—Allowing wine to lie undisturbed in the bottle for a period of weeks, months or years. This allows the tannins in the wine to soften and the wine's components to further harmonize after barrel aging.
Bottle Sickness/Bottle Shock—Moving wine within the winery, bottling it, or transporting it to a different location can have a temporary negative effect on the flavor. After a period of time—a few days or weeks—it will be back to normal.
Bouquet—The smells from older wines, primarily resulting from the winemaking process and from aging.
Brix—A measurement of dissolved compounds in grape juice that approximately indicates the sugar content of unharvested grapes. Most grapes are picked between 21 and 25 degrees Brix. These will produce wines with an alcohol content between 12 to 15 percent.
Brut—French for "dry". A style of sparkling wine that has little, or no, residual sugar.
Bud Break—The time in early spring when new shoots emerge from the buds on a vine.
Bung—The stopper that goes in the "bung hole" in a wine barrel.
Buttery—A taste associated with Chardonnay after it has gone through Malolactic Fermentation. In extreme cases, it can taste like movie theater popcorn butter.
Cane—Older shoots on the vine that have become large and woody.
Canopy—The leaves and shoots of a grapevine.
Cap—When red wine ferments, carbon dioxide is produced which rises to the top of the tank. As it does, it pushes up the skins and seeds to the top, forming a "cap".
Capsule—The "wrapper" placed over the cork to help seal and protect it. Also called Foil. Originally of lead, now made of plastic, tin or paper.
Carbonic Maceration—Fermentation of whole grapes without crushing them.
Cask—A wooden barrel. Frequently used to refer to very large barrels.
Champagne—Sparkling wine made in the Champagne region of France.
Clarification—Making the wine clear by removing sediment.
Cluster—A single "bunch" of grapes.
Cold Stabilization—Lowering the temperature of a wine to 32°F causes the tartrates and other solids in the wine to precipitate and sink to the bottom of the tank, leaving a clearer (clarified) wine. This prevents the formation of tartaric crystals, sometimes called Wine Diamonds, in the bottle after the customer has purchased it.
Cooper—A person who makes or repairs barrels.
Cordon—A method of pruning leaving one cane (cordon) on each side of the trunk.
Cork—A wine bottle stopper made from the bark of oak trees, usually from Spain or Portugal.
Corkage—Fee charged by a restaurant for providing glasses to, and opening a bottle for, a customer who brings his own wine. Fees in the Napa Valley range from $5 - $50, although some restaurants have discontinued the charge.
Corked—A wine that has been tainted by a bad cork that has a mold that produces a chemical compound called TCA (Trichloroanisole). This "dirty sock" or "wet newspaper" smell results in a wine that is said to be "corked" or "corky".
Creamy—Wines that have undergone Malolactic Fermentation can have a rich, smooth feel that is referred to as "creamy".
Crisp—A young, fresh wine with good acid.
Crush—Harvest. When the grapes are picked and crushed. In the Napa Valley, this starts in late August (when grapes with low sugar levels are picked for sparkling wines) and usually goes through most of October, when thicker-skinned grapes finally mature.
Decant—Wine that was not filtered by the winemaker is often carefully poured into another container—usually a decanter—leaving the sediment at the bottom of the first container. Decanting can also aerate a wine, "opening up" its flavors and aromas.
(De)Stemmer Crusher—The machine, used by most wineries, which removes the stems from, and gently crushes the skins of, grapes that have just been harvested.
Dosage—A small amount of sweet wine added to the top of a bottle-fermented sparkling wine, to replace the yeast sediment that is removed just before final corking.
Dry—The absence of sugar in a wine. A wine with no residual sugar is totally dry. It is possible to have a slight amount of residual sugar, and still taste dry to most people.
Early Harvest—Wine made from grapes that are picked early in the harvest, when their acids are high and their sugar content is low.
Enologist—One who practices Enology.
Enology—The science and study of winemaking. Also spelled Oenology.
Estate Bottled—One hundred percent of the wine must be made from grapes grown in vineyards owned or controlled by the winery in the same appellation as the winery.
Esters—Chemical compounds responsible for much of the bouquet and aroma of wines. Swirling wine before tasting "volatizes the esters", enhancing the nose of the wine.
Fat—Rich and full-bodied wine.
Fermentation—The chemical process of converting grape juice to alcohol. This is done by yeast, which converts the natural sugar in the juice into alcohol—and also produces carbon dioxide, which is released out the top of the tanks. (In sparkling wine, the carbon dioxide is retained).
Filtering—Removing particles (yeast, pieces of skin) from wine by passing it through physical filters. This makes the wine clearer and prevents any further fermentation.
Fining—A technique for clarifying wine. Europeans used to use ox blood. Today common fining agents are egg whites, gelatin, bentonite or diatomaceous earth. The fining agent combines with particles in the wine, causing them to settle to the bottom of the tank.
Finish—The taste that lingers in your mouth after you've swallowed the wine. It includes both the type of taste and its length, i.e. a wine can have a "long finish".
Flabby—A wine that is too soft, lacks sufficient acidity, has no "structure".
Foil—Same as Capsule.
Fortified Wine—A wine to which alcohol has been added, such as Port.
Foxy—The distinctive character of wine made from vinifera labrusca, the native American grapes of which Concord grapes are an example.
Free Run—The juice released after the grapes are crushed. It is usually a higher quality than "press juice", which is obtained by squeezing the grapes.
Fruit—How grape growers usually refer to grapes.
Fruity—The natural taste of the grape, more obvious in younger wines. A dry wine can taste sweet due to its intense fruitiness.
Glassy-Winged Sharpshooter—An insect that spreads Pierce's Disease.
Glycerine—An alcohol, formed during fermentation from grape sugar, that contributes to the body of a wine.
Grafting—Splicing a vine of one type onto a rootstock of another type.
Harvest—The time of the year when the grapes are picked. Same as Crush.
Hot—A wine with overdominant alcohol.
Inoculation—Adding yeast to juice to start fermentation.
Late Harvest—Wine, usually dessert wine, produced from grapes picked late in the harvest, when their sugar content is high and their acids are low.
Lees—The sediment that accumulates in the bottom of a container during fermentation. Some wine is aged "on the lees" ("sur lie").
Legs—Also called "tears". The streaks of wine that form and slide down the inside of a glass after you've swirled the wine. An indication of "body". If the legs are wide and thick and move slowly down the glass, the wine can be said to have "nice legs".
Maceration—The extraction, during fermentation, of color, tannin and aromas from the skins and seeds to the juice. Wine juice itself has little color. The color comes primarily from the skins.
Magnum—A double-sized bottle holding 1500 milliliters of wine.
Malic Acid—The "apple" acid found naturally in grapes which can be converted to lactic acid during Malolactic Fermentation.
Malolactic Fermentation—Also known as "ML" or "Secondary Fermentation". A process by which the malic acid (as in apples) in wine is converted to lactic acid (as in the acid found in dairy products). This softens the acid, making the wine smoother and creamier.
Mature—A wine is mature when it is ready to drink. This can be a short time after fermentation for a light, fruity white wine, or many years later for a heavy red wine.
Mercaptans—A smell resulting from too much sulfur. Smells like garlic or rubber.
Meritage—A marketing name that the California wine industry invented for a Bordeaux-style wine that blends such varieties as Cabernet Sauvignon, Merlot, Cabernet France, Malbec and Petite Verdot.
Methode Champenoise—The classic Champagne method of making sparkling wine. Secondary fermentation takes place in the bottle, and the carbon dioxide produced is captured as bubbles.
Microclimate—A small area with unique climatic conditions. These conditions can be quite different from a neighboring area. They include temperature, sunlight, rain and fog.
Miniscus—The top line of liquid in a container. The miniscus in a wine glass should appear clear. (Note: This is a good "bar bet" item. You'll find very few wine drinkers who know what a miniscus is.)
Must—The skin, seeds and juice after the grapes have been crushed. Red wines are fermented as must. For white wines, the must is pressed and only the resulting juice is fermented.
Nose—The smell of a wine, including both Aroma and Bouquet.
Oaky—A strong taste of tannins in the wine due to its contact with oak.
Oxidized—Just as a slice of apple turns brown, so can wine be affected by oxygen. A little is good, too much isn't. A wine that has been exposed to too much oxygen is "oxidized". It tastes flat, tired and old.
Palate—One's ability to taste the subtleties and complexities of a wine. One is said to have a "good palate".
Phylloxera—A tiny louse that damages the roots of vines. During the 1990s, many thousands of acres of grapevines were replaced in the Napa Valley, and throughout California, due to phylloxera.
Pierce's Disease—A plant disease caused by a bacterium that attacks the vine's water-conducting system. Spread by the Blue Green and Glassy-Winged Sharpshooters.
Pomace—Grape skins, seeds, stems and pulp that remain after the grapes have been pressed. Often used as compost.
Press—The machine that gently presses the grapes to squeeze out their juice. Usually an inflatable rubber "bladder" press.
Press Juice—The juice obtained after grapes are pressed.
Pump Over—The process of pumping fermenting wine over the Cap. (This used to be done by hand and was called "punching the cap". It is still done this way in some wineries.) Pumping over gives the wine more contact with the cap, extracting more color, flavor and tannins from the skins and seeds in the cap.
Punt—The concave indentation in the bottom of a bottle.
Racking—Moving wine from one container to another. This is done to clarify wine, to aerate it, or to move it into another container for a different stage in the process, i.e from fermentation to barrel aging. Racking can be done by gravity or with a pump.
Reserve—A wine designated as special by the winery that produces it. There are no quality standards or regulations that apply to the use of "Reserve" or "Private Reserve" or "Vintner's Reserve".
Residual Sugar—The amount of sugar remaining in a wine after fermentation. For most dry wines, the residual sugar is so low that it is below the threshold of most people's ability to taste.
Riddling—In sparkling wine, the turning (traditionally by hand) of the bottle one-eighth of a turn every day. Over time this causes the yeast in the wine to end up in the neck of the bottle, from where it is eventually removed.
Room Temperature—The ideal temperature for serving red wine. This is probably not your room temperature. This is basically the room temperature of a European castle without central heating. Should be 55°-65°F.
Rootstock—The roots of a vine.
Rosé—A wine with very little red color and usually some slight carbonation. The light color results from minimal contact between the juice and the skins.
Rutherford Dust—The legendary reason why Cabernet Sauvignon grapes grown in the soil of the Rutherford area produce such excellent wines.
Second Label—A wine sold by a winery that has a different brand than that of the winery's main wines. It is usually less expensive and, although not always, of lesser quality.
Second Pick—Home winemakers and others will often be given the opportunity to have "Second Pick". They go through an already harvested vineyard and pick grapes that were missed or that matured after the first picking.
Secondary Fermentation—See Malolactic Fermentation
Sediment—Pieces of dead yeast cells, skin and other materials that can sink to the bottom of an unfiltered red wine.
Sommelier (som-MAL-ee-ay)—The knowledgeable person at better restaurants who can give you advice and answer questions about wine. Often wears the traditional tastevin cup attached to a chain around his neck.
Sparkling Wine—Bubbling wine made usually from Pinot Noir and Chardonnay grapes. When made in the Champagne region of France, it's called Champagne. Napa Valley vintners respect the French rights to that term, and call theirs "sparkling wine".
Stems/Stemmy—A tannic taste of stems in a red wine.
Still Wine—A wine with no carbonation—no bubbles.
Structure—All the components of a wine and how well they work together.
Sulfur/Sulfites—Elemental sulfur is used in the vineyards to prevent a fungus called powdery mildew. Sulfur dioxide (SO2) is used during fermentation to prevent oxidation, to inhibit wild yeast, and as a preservative. (Too much sulfur can give a wine a "rotten egg" smell.) Sulfur is also used to clean barrels. Some people are allergic to sulfites in wine, which occur naturally at low levels. For this reason, the label must say "Contains sulfites".
Sur Lie (Sir-LEE)—French for "on the lees". Some white wines are barrel-aged in contact with dead yeast cells to produce a richer, yeastier-tasting wine.
Sweet—The impression of a sugary taste. It can come from residual sugar, or from the fruity flavor of the grape.
Tannin—Causes the astringent, mouth-puckering sensation. Much more predominant in red wines. Comes from skins, seeds, stems and oak. Helps preserve the wine and give it aging potential. With proper aging, tannins can soften to produce a velvety wine.
Tart—A wine that is too high in acid.
Tartrates—See Wine Diamonds
Taste—The sensation in the mouth of bitter, sweet or sour.
Terroir—French term for the growing conditions of a vineyard, including soil, elevation, climate, slope, and a variety of other factors.
Thief/Wine Thief—A glass tube used to sample wine directly from a barrel.
Thin—Lacking in body.
Tight—A closedness and underdeveloped quality of a wine where its flavors and aromas are not yet revealed.
Toast—To heat the inside of an oak barrel. This "caramelizes" its flavors.
Top Up—During barrel aging, wine can evaporate. Cellar workers "top up" the barrel by adding wine to replace the evaporated wine. This removes air from the barrel and prevents oxidation.
Trellising—Training a vine to grow on wires and stakes for better support and exposure to sunlight.
Unfiltered—Wine that has not gone through filtration. Many consumers and winemakers prefer wines that have had as little treatment as possible.
Ullage (UL-ij)—The space in a bottle between the wine and the cork. Also called "headspace". If there is too much, the bottle has obviously leaked.
Varietal—A wine made from one type of grape, such as Chardonnay.
Varietal Character—The unique character of a specific variety of grape. For example, Sauvignon Blanc is known for its "new-mown hay" or "grassy" character. Cabernet Sauvignon is associated with black currant, green olive, herb and bell pepper.
Variety—A particular type of grape, such as Cabernet Sauvignon or Chardonnay.
Veraison (Vay-ray-ZON)—The stage in the growing process when grapes begin to acquire their color. Takes place in the summer.
Vinification—The process of making wine from grape juice.
Vintage—The year in which a wine's grapes were harvested.
Vintner—Technically, the person who blends wine. Generally used these days for the person who owns the winery. In a small winery, this person might also be the winemaker.
Viticultural Area—See AVA
Viticulture—The study and practice of growing grapes.
Vitis labrusca—Native American grapes such as Concord grapes, that are considered of much lower quality for wine than Vitis Vinifera.
Vitis vinifera—European grape species to which most wine grapes belong.
White Grapes—Used to make white wines. Actually green in color.
Wild Yeast—Yeast that naturally occurs on grape skins.
Wine Diamonds—A romantic name for the crystals of tartaric acid (sodium bitartrate—the ingredient of Cream of Tartar) that can form in the bottle or on the cork. Although harmless, not everyone likes to see them, so many winemakers put their wine through Cold Stabilization to prevent this from happening.
Winemaker—The person who is in charge of the process of actually making the wine.
Yeast—Single-celled organisms that produce enzymes that convert sugar to alcohol and carbon dioxide. There is natural yeast on the grape skins, but most winemakers neutralize this "wild yeast" and use a commercial yeast of their choice.
Yield—The production of a vineyard in tons per acre. A lower yield is said to produce grapes of greater quality and intensity. Sometimes it's just a lower yield.