The vinification: a fundamental phase for the wine production
From the grapes to the wine: phases and methods of the wine production
The process that goes from the wine treading to the wine production is called vinification. The first phase of the vinification is the alcoholic fermentation, when the Saccharomyces yeasts transform the sugar of the must into alcohol, carbon dioxide and other elements such as glycerol, methanol, acetic acid, succinic acid and other superior alcohols.
The red vinification
There are three types of vinification. The red vinification is a process that allows the production of red wines. Like the other vinification process, the first step is the removal of the stalks, which means the separation of the woody stalk from the must to avoid the transfer of tannin substances that can give to the wine a bitter taste. After this, the must is pushed in the fermentation tanks that can be made with steel, wood, fiberglass or cement, open or close and with or without moving systems.
The vinification of the red wine foresees that the peels macerate in the must for a period that can varies from 4-6 days to 20-30 days. During the fermentation, the pomace tend to rise on the surface, making the so-called “hat” (in Italian Cappello) that has to be frequently broken to avoid that the contact with the air make the must oxidized and sour, ruining it.
It is fundamental for the fermentation to keep continuously the perfect temperature, to allow the growing of the yeasts. Once the fermentation has finished, there is the so-called “svinatura”, that is the separation of the wine from the pomace.
The white vinification
The white vinification can be realized starting from red or white grapes: the grapes are slightly treaded with horizontal presses.
The must can be fermented purely, removing immediately any element such as peels, stalks and seeds. For this aim it is possible to use clarifiers, settling, centrifugation or filtration. Then, the real fermentation starts adding selected yeasts at a temperature of 18-20°C.
Sometimes, instead, the white vinification can foresees that the pomace stays in the must for a short period of time, thanks to particular techniques. One of them is the cryomaceration, which consists to keep the pomace in contact with the cold must at 5°C for 24 hours. This technique give birth to wines with a richer taste.
Another technique is the pellicular maceration, which foresees the contact between pomace and must at a temperature of 18-22°C for few hours to allow the transfer of the aromatic substances to give intensity and strength to the bouquet.
The rosé vinification
Finally, the rosé vinification is obtained from white and red grapes. The maceration time of the must is really short, no more than 36 hours. This allows the transfer of a small quantity of tannin from the pomace which give a lightly rosé colour to the wine.
The carbonic maceration
There is a fourth type of vinification, widely spread in France for the production of new wines such as the Beaujolais Nouveau: the carbonic maceration. Here the grapes are placed for 7-20 days intact, not treaded, in containers without air and full of carbon dioxide.
The fermentation that occurs in this condition is called intra-cellular, this mean that the fermentation takes place inside the grape. Then, the grapes are treaded and “svinati” (the wine is separated from the pomace). The result is a strongly coloured wine, fresh and fruity.
The malolactic fermentation
Once ended the alcoholic fermentation, it starts in a spontaneous way the malolactic fermentation, which consists in a real and natural de-acidification of the wine: the bacteria transform the malic acid in the lactic acid, with a weak taste. This allows the weakness of the acidity of the product.
Wine is enriched with perfumes and flavours and it is ready for the ripening, when it will gain clarity and strength. Talking about important wines, after this stage usually occurs the the bottle refining and the aging in barrique, where the product is enriched further to reach its maximum expression.
Thus, a lot of phases: a long and delicate process that needs the maximum competence to give raise to a wine that is the expression of the excellence of the land.