Once the vat is full, it is sealed. The seeds as well as the grape juice remain in the vat for 72 hours: this is called alcoholic soaking.

Alcoholic fermentation begins in about 3 days after the harvest. The process is as follows:

There are several kinds of yeast found on the skin of ripe grapes. However, there is only one kind that can induce the chemical reaction with grape sugars to produce alcohol. This yeast multiplies itself very fast in the must during fermentation and reacts with the natural sugars present in the pulp – glucose and fructose.

For this to happen, the juice from the vat is made to flow into a tub to aerate it, it is then pumped to the top of the vat: this is called aerated recoopering. The recoopering also consists in sinking in the “marc hat” created by the seeds that have risen to the surface of the vat, thanks to the carbon dioxide in the fermenting wine, to extract colour and tannins from the grapes.

The principal means for the winemaker to conduct fermentations is to control the temperature, as the yeasts are most active in the temperature range of 12° to 37°.
Actually, Mr. Francisco is equipped with a thermoregulation system that allows him to control the temperature very precisely.

Alcoholic fermentation lasts for about 8 to 10 days, thereafter the wine remains in the vat for 4 to 5 weeks: this is called the soaking period.

• In the closed vat, the wine works alone. It is then that malolactic fermentation begins, a second fermentation due to bacteria and not yeasts anymore.
This reduces the acidity of the wine and contributes to its complexity and stability. These are lactic bacteria that transform malic acid into lactic acid.

•During alcoholic fermentation, the seeds are made to rise to the surface of the vat thanks to carbon dioxide. Thus, a “hat” is formed: the marc.
After a long period of soaking of the marc and the juice, the winemaker runs off the first pressings, by opening the tap at the base of the vat, in order to separate the juice from the marc. This wine is decanted into another vat.
Then it is time for devatting: the marc that has remained in the vat after the first pressings have been discharged is extracted.
This marc is pressed: this gives the press wine, rich in tannins and pigments. It is collected in different proportions, with the first pressings, to add characteristic and longevity to it.