This glossary will be a work in progress and hopefully expand as time goes on, depending on your need for knowledge. In other words it will evolve, so refer back to this from time to time and if you do not find the answers you seek, please let me know and I will do more than would be humanly expected of me, to find an answer for you.
Wine is really incredibly complicated and even living with what we think is amazing technology, we still do not fully understand all of the intricacies of making a beverage that has been produced for thousands of years. I do not want to dumb this glossary up or down (hmmm, maybe dumbing up is not possible), but I only want to give you the information you want and need. Wine knowledge, winemaking and wine chemistry is much more complicated than this glossary eludes to, so if you want to go there, I can go there with you – just let me know. But for most people that enjoy wine or collect wine, the desire to understand every concept of the process is probably fairly, not there.
I could have just linked you to another glossary or reference but I wouldn’t be able to sleep at night knowing that most other web–based glossaries were just regurgitated without any thought put into the process by its proprietor, or incomplete, or even worse, irrelevant. I went through many sources of consumer and professional information to come up with the text for these glossary subjects. Go to the 1855 Forum and start a new discussion or email me directly if I can help you better understand wine. I love this stuff! As I said, I expect this glossary to expand with time so check back.
The total amount of acid in the must or finished wine, which is the sum of fixed and volatile acids. Insufficient acidity in the must will result in a poor fermentation and a slightly medicinal and flat taste. Too much acid will give the wine an unpleasant sourness or tartness. Some acid is necessary for fermentation, and up to one-fourth of the initial acid content will be consumed by the yeast during fermentation.
A very important flavor element in wine, acids provide sour and tart flavors, which balance with other components. Although wines can have a number of acids, amongst the most important are tartaric and malic acid naturally present in grapes, and lactic and succinic acid which are produced during fermentation. Also important is acetic acid found in vinegar, and is formed by bacteria (acetobacter) when subject to oxygen. All wines have a little of this acetic acid because of fermentation but too much obviously spoils wine. Acids also play a part in a wine’s color, sense of taste freshness, and the effectiveness of sulfur dioxide used in the winemaking process.
The lingering flavor and mouth-feel that remain after a wine is tasted. Also known as Finish, although this word has other meanings associated with wine. A long aftertaste is a desirable characteristic to find in wine and often indicates the structure and complexity of the wine. Also see finish.
A process of allowing wine to mature, whether at the winery in barrels or cellared somewhere in bottles. Aging can smooth out acidity and tannins over time as a wine’s chemical compounds react to very minute amounts of oxygen or combine with other compounds. Aging a wine can have profound effects on the complexity of a wine’s bouquet and flavors and so far, there are no substitutes for age. Not all wines are age worthy however, and wines that are aged past their prime will become faded and undrinkable. Also known as maturation.
Also know as ethyl alcohol or ethanol and is produced by yeast fermentation of the grape’s sugars. Typically wines have total alcohol by volume in the range of 9% to 14%. In recent years however, and due to warmer climatic conditions, grapes are ripening more easily, and with the same amount of hang-time (time on the vine) are producing a greater concentration of sugar, thus higher alcohol. This issue of higher alcohol levels found in many of today’s wines is becoming a subject of great debate by winemakers and consumers alike.
Part of the family of phenolic compounds present in red wine that imparts color. This is accomplished during winemaking by allowing the must to make contact with the skins of red grapes, which interact with other components to form pigmented polymers.
Chemical compounds that inhibit or prevent oxidation in wine, usually in the form of sulfur dioxide or less often used, ascorbic acid.
This term is generally used for younger wines and refers to the odor of its fruity characteristic or varietal characteristics. See also nose and bouquet.
A drying sensation in the mouth due to the presence of tannins in wine, which originates from grape skins, seeds, vegetal stems and, to a lesser extent, aging in oak. This sensation is similar to drinking highly extracted tea and is more pronounced in young or immature red wines and usually mellows with aging.
The initial impression of taste as a wine first hits the palate. After attack flavor should flow into the mid-palate, then the finish.
The relative proportions of fruit, alcohol, tannins and acidity, with none of these elements overpowering any other. When all components are ‘in balance’ it is indicative of a well-made wine.
A taste sensation detected by taste buds of the tongue, and not very common in wine. It is sometimes mistaken for astringency or even sourness and is considered a flaw if it has a pronounced presence in wine.
Weight or texture in the mouth based primarily on the glycerol content, which is a byproduct of winemaking. A wine’s body is a function of alcohol and extract, and is also closely related to the grape from which the wine was made. Some wines will always have a lot of body while other never will. Full-bodied wines may sometimes be referred to as ‘chewy’, which is to say dense and rich while light-bodied wines may be referred to as ‘thin’. See also mouth-feel.
Blended wines made with two or more of the traditional Bordeaux grape varieties. Bordeaux red grapes are Cabernet Sauvignon, Merlot, Cabernet Franc, Petite Verdot, and to a lesser extent Carmenère, Gros Verdot, Malbec, and St. Macaire. Grapes used for white Bordeaux are Sauvignon Blanc, Muscadelle, and Sémillon.
A subject of some controversy as it has not been proven nor disproved but the concept is that wine becomes ‘bottle sick’ for a period of time following bottling or transportation. This is different from a bottle going dumb.
Is actually a fungal disease that attacks ripe grapes while on the vine. With the proper grapes in the right climate, botrytis, also known as ‘noble rot’, causes water content to escape from the grape, which greatly concentrates the sugar content and flavor. Wines made from noble rot are considered to be the best dessert wines in the world and generally come from regions including Sauternes (Bordeaux), Tokaji (Hungary), and the great Rieslings of Germany. If botrytis gets out of control in the vineyard it becomes malevolent causing what is known as ‘gray rot’ and can quickly wipe out a large amount of fruit in a vineyard, for the season.
Fermentation and aging contribute to this complexity of fragrance but bouquet is mostly attributed to bottle aging. Over time, an age-worthy wine will develop beautiful aromas that cannot be attained any other way and a wine such as a fine quality mature Bordeaux will unfold layer after layer of fragrance, as it will flavor.
A spoilage yeast (a type of fungus, not a bacterium) that is not harmful to humans but can produce pronounced and obvious flaws in wine if found in sufficient concentration. This yeast, also referred to as ‘brett’ is very common at low levels, mostly in reds, and can spread quickly through a winery’s equipment and barrels and once present, is difficult to eliminate completely. Brett can show itself in the form of many different aromas that include sweat, barnyard, ammonia, horsy, band-aid, leathery, manure, smoky and medicinal smells. Some argue that small amounts of brett can actually contribute to a wine’s complexity and is a good thing if in low concentrations.
French for black current, a common descriptor in red wines
Winemaker will at times add sugars to the must in order to balance the wine or compensate for deficiencies in the fruit, such as a lack of ripeness. Grapes lacking ripeness will not only tend to taste ‘green’ but also be unable to produce the desired alcohol content because the fruit itself was unable to produce enough sugar, which can happen when a growing season has unfavorable weather conditions for ripening. This technique is not legal in all wine regions of the world and has limitations in other regions. French chemist Jean-Antoine Chaptal developed the use of this practice the late 19th century.
Multiple layers and nuances of bouquet and flavor that are found mostly in mature wines because aging contributes to this attribute. Complexity creates interest and often unfolds layer upon layer on the nose and in the mouth if the wine is at its peak. Compared to complex wines, other wines seem shallow or one-dimensional.
Wine bottle closure made from the bark of cork oaks (Quercus Suber). Quality corks have very fine grain, only minor or no faults, good compressibility, and have been cured to contain between 5 and 8% moisture.
corked wine/cork taint:
A bottle considered corked will exhibit quite intense aromas of musty, moldy, wet newspaper or wet cardboard; a partially corked wine may have reduced fruit flavors and aromas with a slight smell of taint. A microbe found within the cork itself, known as 2, 4, 6. trichloroanisole, or TCA, is responsible for corked wine. Most people can detect TCA in as little as 5 parts per trillion!
To decant a wine is to pour it from the bottle into a specially shaped container that aerates the wine, which is sometimes left in the vessel over the course of hours or more. Personally I believe that any wine that needs to be decanted for hours is either too young to drink or flawed. The use of a decanter should be fairly limited to the practice of separating sediment from the wine so as to avoid pouring those solids into the glass. Sediment is frequently found in older wines, perhaps six to eight years and older, and if drunk may impart bitterness or other off flavors in wine. See the section on Storing and Drinking Wine for further information.
Not sweet and has little or no residual sugar left over as a result of fermentation.
Lots of room for humor here but I’ll restrain myself and stay on subject: a wine that closes down and goes into a dormant stage for a period of time. Wines in this stage lack aroma and flavor. Winemakers are unable to predict when this may happen or how long a wine might stay in this stage but it could certainly stay dumb for up to several years while the wine transitions from young to mature. This dumb phase, if it is going to happen, usually occurs within a few months after bottling and it does not happen to all wines (usually reds).
The science, discipline or study of winemaking, also spelled oenology.
During fermentation and aging, wine produces compounds from a chemical reaction, which result in contributing aromas that are sweet and slightly fruity.
ethanol or ethyl alcohol:
An alcohol, C2H5OH, produced by distillation or as the principal alcohol in an alcohol fermentation by yeast. Also know as Ethyl Alcohol.
An ester produced by fermentation. When ethyl acetate exists in sufficient quantity, it produces a slightly sweet, fruity, vinegary smell. Too much is considered a flaw.
A very important element of wine that can be determined by both the grape varietal and the winemaker’s decisions. The technical definition of extract is: all substances found in wine that cannot be evaporated for example pigments, sugars, and minerals. Extract determines to a large extent, the wine’s color, body and concentration of flavors. Some grapes are naturally high in extract while others must be coaxed or are better made as lighter wines. A winemaker may encourage greater extract by utilizing a number of techniques such as cold soaking or time the must is left in contact with the grape skins known as maceration and so on.
A wine that has peaked in flavor and complexity and is declining in quality; has passed its prime. This issue is but one of the reasons to implement some sort of wine cellar management. By not managing a cellar’s inventory, it is easy for wines to be purchased that later become undrinkable because the wine was forgotten or misplaced.
The process of yeast converting sugar into alcohol. The chemical reaction also creates other by-products such as carbon dioxide, other acids and alcohols, and glycerol, all of which affect flavor mouth-feel. Yeast is only able to metabolize the six-carbon sugars glucose and fructose. Other sugars present do not convert to alcohol but account typically for less than 0.2 percent of residual sugar and are about ten times lower than the threshold is for people to even detect sweetness.
A sometimes-controversial process of pumping wine through a filter of cellulose or diatomaceous earth to remove minute particles and dead yeast cells which in turn produces wine with visual clarity. Some winemakers argue that filtering wine also removes flavor and color compounds and thus choose to not filter their wines.
The process of removing solid particles suspended in wine using any number of techniques including adding fining materials to the wine such as egg whites, gelatin, casein (milk proteins), or bentonite (clay).
The flavor and texture that remains on the palate after a wine is swallowed. A long finish is considered most desirable and little or no finish is considered lacking, which may also be referred to as a ‘short’ wine or ‘short’ finish. See also attack and mid-palate.
Non-volatile acids typically found naturally in wine grapes and sometime added by the vintner including tartaric, malic and to a lesser extent, citric acids. Fixed acids can change from vintage to vintage because of weather, which in a warmer growing season will have the effect of lowering fixed acids, while a cooler season may produce higher acids. Wines having a good level of fixed acidity have the impression of being fresh, crisp and vibrant, which can be especially important to white wines. Acidity is also what allows white wine to age, as acids are an antioxidant. See also malolactic fermentation.
One of the byproducts of fermentation, glycerol provides body and smoothness with its syrup-like texture and is a slightly sweet, colorless and odorless substance; may also be referred to as glycerin.
Although this is a tasting note, meaning the grapes of a wine are unripe, it also sometimes refers to phenolic compounds in the grapes and tannins, which can be harsh when young or unripe. In its physical form, most tannins are derived from grape seeds and before they mature into a brown color from ripening on the vine, they are visually green, which can impart unripe flavors or extremely dry, tannic responses on the palate.
Excessive alcohol that may become undesirable because it throws the wine out of balance.
Hydrogen sulfide (H2S) is a product of yeast combining with sulfur. Too much H2S creates mercaptans which can create undesirable rotten-egg-like or sewage aromas in wine and is of course considered a serious flaw.
The process of adding yeast to the must to start fermentation or malolactic fermentation.
After swirling wine in a glass, legs of a viscous nature (or sheets) will appear, running down the inside of the glass, which is indicative of alcohol levels and the body of the wine.
The period of time must is in contact with the skins and seeds. The winemaker may prescribe extended maceration after primary fermentation to extract even more flavors, aromas or color from the grape skins.
A process that may be referred to as secondary fermentation (although no alcohol is produced in this process) that converts malic acid into a softer, more palatable, lactic acid, which can make some wines smoother on the palate. As a byproduct, flavors of butter can be produced which produces desirable complexity to some wines such as Chardonnay. The downside is that malolactic fermentation is also known to reduce the fruit flavors in some wines so it becomes another important stylistic decision to make by the winemaker.
After the wine’s initial taste on the palate (attack), the impression of taste goes to a middle stage of perceptible flavor before swallowing and experiencing the finish. The mid-palate seems to be one of the more difficult components to obtain in wine; many wines have good attack and acceptable finish but lack flavor in between. A wine considered a ‘fine wine’ will a definitive and distinctive attack, mid-palate and finish.
Related to texture on the palate or in the mouth, producing impressions of having weight or being thin or thick bodied. Higher alcohol and glycerol content contribute to the body of wine and can make a wine feel ‘big’ in the mouth.
The composition of the grape’s juice and solids after being crushed for the purpose of fermentation.
The fragrance of a wine and how it smells, although aroma or nose is usually used for younger wines and the term bouquet is usually reserved for older or mature wines.
A huge and specialized subject in and of itself, oak it is a type of wood from a specific tree species used to make barrels for aging and which impart flavors and aroma in wine. Much variation is available to winemakers and results depend on where the oak comes from (French and American are used most often, although Hungarian oak is now coming into the market because of price), if the barrel is new or used (used barrels loose the ability to impart its characteristics at a rate of about 20% per year), and what level of ‘toasting’ the barrel went through by the cooper (the barrel maker). Oak itself produces chemicals into wine known as lactones and without getting into deep chemistry, some of the flavors and aromas transferred to wine through oak include sweetness/butterscotch, fresh oak/coconut, vanilla, clove/spices and smoke. Used barrels may be desirable in some instances so as to not overwhelm the wine itself with oak (also known as woodiness) but one of the major issues with used barrels is that they can be sanitized but not sterilized; this creates great opportunities for problems such as Brettanomyces to run rampant throughout the winery’s equipment. ‘Oaking’ on the other hand is a process used to bypass the expense of buying barrels by putting oak chips, cubes or staves into wine. The debate about this practice runs high, as one might expect.
The process of oxygen reaching wine, whether in barrel, bottle or glass. Oxygen reacts differently in each case, to wine molecules and causes premature aging unless the wine is in a glass and ready to be drunk. Oxidized wine flavors become dull, have off-odors and red wines become brownish in color and are ultimately undrinkable. Fading is caused by oxidation and is very undesirable.
[p]otential of [H]ydrogen, used to express relative acidity or alkalinity in a liquid solution, in terms of strength rather than amount, on a logarithmic scale of 0 to 14. A pH of 7 is neutral; above 7 expresses more alkalinity and below 7 expresses more acidity.
These compounds include tannins from grape skins, grape seeds and oak, along with color pigments. Also known as phenols and phenolics, these chemical substances contribute to, astringency, color (anthocyanins), and bitterness and other flavors (flavan-3-ols, flavanoids, and polyphenols) and odors. Phenolics are very important to red wines and much less so to whites.
This is the first fermentation where sugars from the must are converted into alcohol. Malolactic fermentation is considered secondary fermentation.
Sugar remaining in wine after fermentation is complete or is permanently halted by stabilization (by the winemaker). Eventually enough alcohol is produced so that it becomes toxic to the yeast and they die or when there is no more sugar for yeast to consume.
Occurs when molecules attach to each other forming a solid and fall out of liquid suspension. A most recent theory speculates that tannin molecules attach to color pigment molecules, which might explain partially why a red wine’s tannins soften over time. Sediment is typically found in higher-end wine and older wines, usually reds. These solids can impart bitter flavors into the wine and thus should be separated by using a decanter. For more information about decanting, see
A tart taste in wines that usually come from acids and ethyl acetate. A wine’s pH plays a determining role in how sour it may taste. Order of decreasing sourness: tartaric, malic, citric, lactic, and succinic. Wines with a pH less than 3.1 or a titratable acidity more than 0.9% will taste sour.
sulfur dioxide/sulfites/free SO2:
One of the most important tools of a winemaker, sulfur dioxide is introduced usually after crushing the grapes for fermentation to restrict microbial activity, and then again in other steps of the winemaking process which protect the wine from oxidation. Free SO2 is that which does not bind to other chemicals in the wine and depends on the wine’s pH. The bound SO2 is not useful to the winemaker because it is attached to other wine components and cannot be used as antimicrobial or for antioxidant purposes. Sulfites are better added to wine infrequently but in larger quantity, as opposed to smaller doses on a more frequent basis. If you own a swimming pool, you’ll understand this concept when you ‘shock’ your pool every year in the spring season. Sulfur is very important to wine chemistry and without it, wine would spoil through oxidation and have all sorts of microbial activity throughout.
This substance occurs naturally in grapes and other consumables (such as tea) and provides structure for wine to age because they are a natural antioxidant. The source of tannins is from the grapes skins and seeds (red wines are in contact with grape skins and seeds much longer than white wines, which do not relay on skin contact) and sometimes the stems from grape clusters. Tannins are responsible for the feeling of dryness in the mouth when drinking red wine, while white wines are more oriented around acidity.
The impression of viscosity or weight, or the lack thereof, on the palate.
How much air exists between the bottom of the cork and the surface of the wine in a bottle. It is not uncommon for older wines to have ‘lost’ some wine due to aging (evaporation) but extremes can point to leakage, cork failure, oxidation, poor storage conditions, questionable provenance or other problems. Consult me before you buy, if in doubt.
Refers to what the wine’s dominant grape variety is, for example, Cabernet Sauvignon or Merlot. Technically, more than 95% of wine varietals are derived from the subspecies of Vitis Vinifera.
These are acids that can evaporate or be altered and is not stable, as opposed to fixed acids, which cannot be altered. Acetic acid and Butyric acid make a major contribution to a wine’s bouquet and are two of the principle volatile acids found in wine. If these acids are too intense however, the wine will be considered flawed.
Yeast is a unicellular fungi cultured especially for winemaking and chosen by the winemaker for its attributes, which can include flavor enhancement. A wild yeast or indigenous yeast may be any mixture of the thousands of yeast strains that are naturally airborne or already on the fruit.
I got nothing – sorry.