Characterization of red wines

Red wines are produced only from red grapes with either colored or uncolored juice. The grape type is of vital importance to the qualities of the red wine. High quality red wines are obtained from grape varieties with a large technological stock of dyes. In addition to the variety, the technology of production of red wine has a great affect on quality. Through the use of diverse technological operations, temperature regimes, different kinds of yeast, among others, the contents of the wine can be affected, thus improving its quality. Red wine acquires qualities that distinguish it greatly from white wines. The most significant differences can be found in the color, taste, and chemical composition.

Color

The color of red wines is lighter or darker, depending on the grape variety, wine type, and local conditions. The color of young red wines is more intensive with violet and purplish tones to a certain extent. With one- or more year old wines it is a ruby red, while with the high-quality, bottle- and oak barrel matured wines, brick red hues appear.

The color intensity of red wines depends on the quantity of anthocyanins, which form the red coloration, and on the products of the condensation of the anthocyanins with the tannins. A number of objective indicators of color assessment have been derived, the most significant of which are nuance and intensity. The wine color is also characterized by a subjective method – organoleptic analysis. The monitored indicators here are clarity, nuance, and intensity.

Aroma

The aroma of red wines naturally differs greatly from that of the white types, as the aromatic elements are 2 to 4 times more. In the group of general smelling substances, the high alcohols are a dominating force, mainly determining the fermentation scent. That scent is complemented by esters, aldehydes, Diacetyl, among others.
Unlike white wines, red wines have greater amounts of volatile fatty acids. The quantity of the ingredients that determine the red wine aroma, and their ratio, are defined by the temperature at which the fermentation takes place. At a temperature in the range of 24-26°C for the fermentation mass, red wines with enhanced fruit tones are produced. At a low pH level and high acidity of the grape pulp, the fruity essence of red wines is increased. All of these flavors stand out thanks to the ethanol.
The scent is not always organoleptically assessed using the indicators of purity, intensity, subtlety, nuance, and harmony.

Taste

Red wines in particular vary greatly from white wines in taste. They are significantly more powerful, denser, and extractive. This is mainly due to the higher content of phenolic substances, which is from 5 to 10 times more than it is in white wines.
With aged wines the phenolic substances are in condensed forms, projecting a velvety taste and an unmatched softness. For red wines it is very important that the titratable acidity is not high because of the taste interrelation of the tannins and the acids. With reference to the former, it is also necessary to carry out malic lactic fermentation, during which the malic acid – with an otherwise sharp, sour taste, is transformed under the effect of lactic acid bacteria into lactic acid that has a mild, pleasantly sour taste. With this the effect of “rounding out the edges” of wine’s taste is achieved.
Another important characteristic in achieving softness in taste is producing multivalence alcohols during the fermentation process, Glycerol in particular. It adds the soft attack to the taste that wine has when entering the oral cavity. During organoleptic evaluation of flavor and taste of the wine aroma the following parameters are monitored: attack, purity, intensity, body, harmony, durability, and aftertaste.