In the collective historical imagination, wine par excellence is red.
Most likely the first ones wines produced they were red, since the practice of separating the pulp from the peel was not yet known.
The red wine is produced only with red berried grapes but the must, in order to acquire the coloring pigments (anthocyanins and tannins) must remain in contact with the skins (rich in these substances) for a shorter or longer time. The longer this stay (maceration), the greater the coloring. The variety and environmental conditions also affect the chroma of red wines. Some varieties of red grapes (such as cabernet sauvignon), have a higher coloring capacity than other types (see, for example, nebbiolo or pinot noir).
Obviously, a greater coloring capacity also leads to a greater quantity of tannins in red wines, which are fundamental for the body and balance of red wines. Red wine.
It is known that, if not softened by refinement or evolution, tannins are astringent (sometimes even loose), due to the precipitate of the mucin, a saliva lubricating protein which, in contact with tannins, precipitates, determining that characteristic feeling of ligament that is evident in the oral cavity (the mouth dries up and the gums become dry).
The organoleptic quality of astringency is often decisive for the pleasantness and drinkability of a red wine: this is why, if you want to produce quality wines, it is essential that the grapes are ripe from a phenolic point of view. As maturation develops, in fact, tannins take on a softer and velvety, more pleasant organoleptic quality.
But this parameter must also take into account the relationship existing with the other elements that contribute to the balance of red wines, the acidity and sugars present in the grapes.
The ripe grapes, on the basis of the red wine to be produced, are harvested and de-stemmed, that is, the stalk or rachis is eliminated, using a special machine, called the destemmer. Operation necessary for the production of fine red wines, as the polyphenols contained in the stem are particularly astringent and never smooth. After destemming, the red wine berries are pressed to obtain the must. But let's see in more detail the various production phases.
Vinification in red
It is used both for the production of important red wines, suitable for aging in wood, and for ready-to-drink wines. The sequence of necessary operations is as follows:
• Destemming-pressing of the grapes It is carried out with a destemmer - crusher which, by eliminating the stalk (which would give herbaceous tastes and bitter tannins), presses the grape immediately after, thus putting the skin and pulp in contact.
• Inoculation of selected yeasts It is done to have greater security on the good progress of fermentation and, consequently, higher quality on the finished wine.
• Memerged cap aceration - Replacements The production of red wines is characterized by the maceration of the marc with the must. The longer the contact time between the solid part (the marc) and the liquid part (the must), the greater the extraction of the pigments and all the other solid parts, the wine will be so intensely colored.
Maceration is of enormous importance in the production of great red wines, as it allows the solubilization of anthocyanins (coloring substances) and tannins, with a significant influence on the wine extract. Maceration can sometimes be reduced to a minimum or even avoided for light red, rosé and white wines.
In the grape skin, in addition to polyphenols (anthocyanins and tannins), most of the aromatic kit is also found and this is why, in some cases, it becomes important, following particular techniques (cryomaceration), to make a short maceration also for production of white wines.
There are various methods used for the extraction of the color of red wines: the most used is the hat maceration emerged. It is a technique that was used when once the pumps were not as efficient as today and it was therefore almost impossible to carry out the pumping over.
It consisted in trying to keep the pomace hat, which was formed with the start of fermentation, immersed in the must. In this way the only possible mixing was that created by the turbulence of carbon dioxide and the so immersed marc could not undergo abnormal fermentations.
By reassembly, we mean the pumping of the must under the marc cap above the latter, thus causing a real washing of the skins and, consequently, the extraction of the substances contained in them. It is important that reassembly is always carried out during fermentation; otherwise, the must / wine is aerated as it absorbs a considerable quantity of air, while eliminating a considerable quantity of carbon dioxide (slowing the alcoholic fermentation).
However punching down and pumping over serve:
– oxygenate the yeasts and encourage their development;
– standardize the temperature of the mass (cold above and hot below);
– prevent the formation of hydrogen sulfide that forms in an oxygen deficient environment (stinks rotten eggs);
– prevent the marc from contact with the air being altered (i.e. acidifying and oxidizing);
– increase the extraction of color from the marc.
Depending on the red wine that will be obtained, the duration of maceration and the number of pumping over will vary. So for a great red wine, maceration can last from 7 to 15 days and pumping over can be from 2 to 4 per day for the duration of fermentation.
For a light red or rosé wine, however, maceration will be reduced to a few hours (12 - 48) while pumping over to just 2 or 4 in all. If you want to prolong the contact of the marc with the wine beyond fermentation, you will have to switch to the submerged cap.
• Temperature control in fermentation Essential practice to achieve balance between olfactory breadth and gustatory harmony. The temperature is maintained around 27/30 ° C. to promote, together with pumping over, the extraction of color.
• End of fermentation It is decided at this point the drawing off or the prolongation of the maceration with the submerged cap.
• racking It consists in transferring the wine into another wine jar separating it from the marc.
• Flower wine It is the wine obtained from racking, plus any draining from the press before the pressing cycle begins.
• Pressing of the marc It is carried out with presses or presses (hydraulic or pneumatic) in order to extract the wine retained by the marc as much as possible; the product obtained is normally rich in color, tannins and extract and organoleptically it is herbaceous and disharmonious. For these characteristics it is normally used to correct, with the cut, other wines of lesser value, scarce in these components. The depleted marcs are sent to the distillery for the production of grappa.
• Racking After racking, the wine experiences a quiet moment, in which the particles suspended in it (yeasts, bacteria, colloids, fragments of skins, fragments of pulp, etc.) slowly settle on the bottom of the wine vessel. It is therefore necessary to periodically decant in order to separate the sediment formed by the clear (or clearer) wine above. In this way, it prevents the deposit, deteriorating, from giving unpleasant smells to the wine. The first decantings, which are carried out after racking, are normally carried out by airing the wine (decanting in the air) in such a way as to allow the carbon dioxide dissolved in it to be released. In this way, unpleasant odors which are easily formed in the presence of large quantities of gas will be avoided.
• Malo lactic fermentation It can be stimulated by heating the mass, or left to perform spontaneously as soon as the cellar temperature has risen around 18/20 ° C.
• Maturation Depending on the type of red wine that you intend to produce, different refinement and maturation methods will be adopted. Usually for fresh and immediately ready red wines, stainless steel aging containers will be used; for red wines with greater structure and polyphenolic charge, wooden containers can be used.
Piero Canopoli and Giuliana Dalla Longa