Water is main component of wine and is mostly derived from the pulp of the grapes. It covers on average 70% to 90% of volume, and its aim is to dissolve and mix all other substances.
Ethyl alcohol (also called ethanol) is the second wine compound in terms of volume. Its quantity, measured in percentage by volume and called alcoholic strength, may vary depending on the type of wine. Excluding liqueur and sweet wines, it can occupy an average of 9% to 16% of volume.
Its color is transparent, it may look like water, but its smell is pungent and its taste is particularly burning.
Excluding liqueur wines, where it is added, it is produced during the fermentation phase, which is also called alcoholic fermentation.
Main effects: sensation of warmth and softness
Glycerol, a secondary product of fermentation, together with alcohol gives the wine roundness and softness. In liquid form it has a transparent color, viscous appearance and sweet taste.
It is used in various fields, including as a food additive in the preparation of syrups, where it is known under code E422.
Main effects: sensation of softness
Tartaric acid, naturally present in the grape and transferred to wine during fermentation, is one of the main responsible for the acidity of wine.
In the food field, where it is known with code E334, it is added to candy, jams and juices to give an acidulous taste.
Main effects: salivation, sensation of acidity and freshness
Malic acid, naturally present in the grape and transferred to wine during fermentation, together with tartaric acid is one of the main responsible for the acidity of wine. At room temperature it is a solid, white, with a slight odor.
In colder vintages or in not perfectly ripe grapes, its concentration is due to unpleasant flavors, such as apple peel. In these cases malolactic fermentation is used to make it lactic, softer and less aggressive.
Main effects: salivation, sensation of strong acidity
Lactic acid is a product of malolactic fermentation, during which malic acid is transformed into lactic acid and carbon dioxide. With a less sour taste of malic acid, its presence gives the wine less nuances of hue, softer, spicy and toasted hints.
Malolactic fermentation, which is activated naturally under certain conditions, which, by the addition of bacteria, is usually practiced in red wines and aging whites.
Main effects: salivation, sensation of acidity
Succinic acid, produced during alcoholic fermentation, is one of the responsible of wine acidity. At room temperature it is solid, white and odorless.
Main effects: salivation, sensation of acidity, sapidity, bitterness
Acetic acid is formed by the oxidation of acetaldehyde, a secondary product of fermentation and, above the threshold of 0.5 g / l, gives the wine an unpleasant rather prickly herbaceous odor. In liquid form it has a transparent color.
Its presence in wine is often countered by the use of sulfur dioxide. This one in fact, creating a strong bond with the acetaldehyde molecule, inhibits its unpleasant odoriferous properties. Because sulfur dioxide, especially in large quantities, has a negative effect on human health, maintaining control of acetaldehyde reduces its use, with positive effects on the final product.
Main effects: sensation of harshness
Main sugars are glucose, fructose, xylose, arabinose, and sucrose. They are naturally present in grapes, as they are created during ripening.
The fermentation process does not transform them completely. Depending on the residual concentration, the wine may be dry (<9 g / l) or sweet (> 50 g / l).
Main effects: sweetness and softness sensations
Coloring substances are polyphenolic molecules that give color and body to wine:
- the color of red wines is given by anthocyanins and tannins;
- the color of white wines is given by flavones, chains and leucoantoans and chlorophyll.
Tannins, catenins and leucoantoans are also responsible for the taste of astringency.
Main effects: color, body, astringency sensation
Aromatic substances are molecules that give perfume and taste to wine. Depending on their origin they are distinguished in three categories.
- Primary: they are present in grapes, significantly in the grapes of the Malvasie, Moscatos, Brachetto and Aromatic Traminer;
- Secondary: produced during fermentation;
- Tertiary: produced during the ripening phase.
Main effects: taste-olfactory sensations
The salts of organic acids (tartrates, citrates and sick) and inorganic (chlorides, sulphates, phosphates) come from the grapes and give the wine a sensation of minerality and sapidity. These ones, often, are confused with the feelings of acidity.
Main effects: body, salivation, sensations of sapidity
Carbon dioxide is produced during the fermentation process and, as long as it is not brought to atmospheric pressure (i.e. until you uncork the bottle), is dissolved in the wine in liquid form.
Main effects: bubbles, color vivacity, attenuation of softness, accentuation of hardness
Sulfuric anhydride is a substance naturally occurring in wine and is produced during alcoholic fermentation. The addition of additional sulfur dioxide is intended to preserve the wine from possible alterations and alterations.
Main effects: conservation, sterilization