The color of wine is one of the most easily recognizable characteristics of

wine Wine is an alcoholic drink made from Fermentation in winemaking, fermented fruit. Yeast in winemaking, Yeast consumes the sugar in the fruit and converts it to ethanol and carbon dioxide, releasing heat in the process. Wine is most often made f ...

Color Color (or colour in English in the Commonwealth of Nations, Commonwealth English; American and British English spelling differences#-our, -or, see spelling differences) is the visual perception based on the electromagnetic spectrum. Though co ...

is also an element in wine tasting since heavy wines generally have a deeper color. The accessory traditionally used to judge the wine color was the tastevin, a shallow cup allowing one to see the color of the liquid in the dim light of a cellar. The color is an element in the

classification of wine The classification of wine is based on various criteria including Protected designation of origin, place of origin or appellation, vinification method and style, Sweetness of wine, sweetness and vintage,J. Robinson (ed) ''"The Oxford Companion to W ...

Color origins

The color of the wine mainly depends on the color of the

drupe In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pip'' (UK), ''pit'' (US), ''stone'', or ''pyrena'') of hardened endocarp with a seed ...

of the

grape variety This list of grape varieties includes cultivated grapes, whether used for wine, or eating as a table grape, fresh or dried (raisin, Zante currant, currant, sultana (grape), sultana). For a complete list of all grape species, including those unimp ...

. Since pigments are localized in the center of the grape drupe, not in the juice, the color of the wine depends on the method of vinification and the time the

must Must is freshly crushed Juice, fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes up 7–23% of the total weight of the must. Making must ...

is in contact with those skins, a process called maceration. The Teinturier grape is an exception in that it also has a pigmented pulp. The blending of two or more varieties of grapes can explain the color of certain wines, like the addition of Rubired to intensify redness. Red drupe grapes can produce white wine if they are quickly pressed and the juice not allowed to be in contact with the skins. The color is mainly due to plant pigments, notably phenolic compounds (

anthocyanidin Anthocyanidins are common plant pigments, the aglycones of anthocyanins. They are based on the flavylium cation, an oxonium ion, with various groups substituent, substituted for its hydrogen atoms. They generally change color from red through p ...

tannin Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and Precipitation (chemistry), precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' is widel ...

s, etc.). The color depends on the presence of acids in the wine. It is altered with wine aging by reactions between different active molecules present in the wine, these reactions generally giving rise to a browning of the wine, leading from red to a more tawny color. The use of a wooden barrel (generally oak barrels) in aging also affects the color of the wine. The color of a wine can be partly due to co-pigmentation of anthocyanidins with other non-pigmented flavonoids or natural phenols (cofactors or "copigments").

Rosé A rosé () is a type of wine that incorporates some of the wine color, color from the grape skins, but not enough to qualify it as a red wine. It may be the oldest known type of wine, as it is the most straightforward to make with the Macerati ...

wine is commonly made by the practice of short maceration (exposing wine to red grape skins for only a short period of time in order to give it a lighter feel closer to that of white wine) or by blending a white wine with a red wine.

Color evolution

The presence of a complex mixture of

anthocyanin Anthocyanins (), also called anthocyans, are solubility, water-soluble vacuole, vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart named a chemical compou ...

s and procyanidins can increase the stability of color in wine. As it ages, the wine undergoes chemical autoxidation reactions involving

acetaldehyde Acetaldehyde (IUPAC systematic name ethanal) is an organic compound, organic chemical compound with the chemical formula, formula , sometimes abbreviated as . It is a colorless liquid or gas, boiling near room temperature. It is one of the most ...

of its pigments molecules. The newly formed molecules are more stable to the effect of pH or sulfite bleaching. The new compounds include pyranoanthocyanins like vitisins ( A and B), pinotins and portosins and other polymeric derived pigments. Malvidin glucoside-ethyl-catechin is a flavanol-anthocyanin adduct. Flavanol-anthocyanin adducts are formed during wine ageing through reactions between anthocyanins and tannins present in grape, with yeast metabolites such as

. Acetaldehyde-induced reactions yield ethyl-linked species such as malvidin glucoside-ethyl-catechin. This compound has a better color stability at pH 5.5 than malvidin-3''O''-glucoside. When the pH was increased from 2.2 to 5.5, the solution of the pigment became progressively more violet (''λ''_max = 560 nm at pH 5.5), whereas similar solutions of the anthocyanin were almost colorless at pH 4.0. The exposure of wine to oxygen in limited quantities can be beneficial to the wine. It affects color.

Castavinol Castavinols are natural phenolic compounds found in red wines. These molecules are colorless and are derived from anthocyanin pigments. Thus their formation leads to a wine color loss. Known molecules * Castavinol C1 * Castavinol C2 * Castavinol ...

s are another class of colorless molecules derived from colored

pigments.

In model solutions, colorless compounds, such as catechin, can give rise to new types of pigments. The first step is the formation of colorless dimeric compounds consisting of two flavanol units linked by carboxy- methine bridge. This is followed by the formation of xanthylium salt yellowish pigments and their ethylesters, resulting from the dehydration of the colorless dimers, followed by an oxidation process. The loss of a water molecule takes place between two A ring hydroxyl groups of the colorless dimers.

Colors

The main colors of wine are: * Gray, as in vin gris (''gray wine''). * Orange, as in skin-contact wine, a white wine that has spent some time in contact with its skin, giving it a slightly darker hue. * Red wine (although this is a general term for dark wines, whose color can be as far from "red" as bluish-violet) *

(meaning pinkish in French) * Tawny, as in tawny port. *

White wine White wine is a wine that is Fermentation in winemaking, fermented without undergoing the process of Maceration (wine), maceration, which involves prolonged contact between the juice with the grape skins, seeds, and pulp. The wine color, colou ...

(light colored wine) *

Yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In t ...

(or straw color), see for instance vin jaune, a special and characteristic type of white wine made in the Jura wine region in eastern France, Jurançon or Sauternes. Other: *

Burgundy (color) Burgundy is a purplish dark red color. The color burgundy takes its name from the Burgundy Burgundy wine, wine in France. When referring to the color, "burgundy" is not usually capitalized. Terms describing interchangeable shades, with over ...

, a shade of purplish red * Sangria (color), a color that resembles Sangría wine * Ox blood, probably referring to ancient practice of fining red wines with dry powdered blood File:Beaumes de Venise Blanc et Rosé.jpg, Glasses of Beaumes de Venise white and

rosé A rosé () is a type of wine that incorporates some of the wine color, color from the grape skins, but not enough to qualify it as a red wine. It may be the oldest known type of wine, as it is the most straightforward to make with the Macerati ...

File:Copita-of-amontillado.jpg, Glass of Amontillado

sherry Sherry ( ) is a fortified wine produced from white grapes grown around the city of Jerez de la Frontera in Andalusia, Spain. Sherry is a drink produced in a variety of styles made primarily from the Palomino grape, ranging from light versio ...

File:Baricelli Villa Calcinaia Vin Santo.jpg, A glass of Vin Santo with its characteristic amber color File:Beringer White Zinfandel.jpg, Beringer White Zinfandel

Scientific color determination

The International Organisation of Vine and Wine (OIV) provides methods to assess the color of a wine using a spectrophotometer and the calculation of indices in the Lab color space.

References

External links

Wine color on www.wine-tasting-guide.com
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Oenology