How to make wine: Harvest, Destemming, Crushing, Alcoholic Fermentation and Racking.

End of August 2022, again this year we make wine. The grapes harvested are very scarce but we do it for fun and not to lose the habit and practice of making wine with grapes from our garden, taking advantage of the teaching of Nonno Gigino.
This video shows the first stages of the winemaking process, during which the grapes are transformed into wine.
Phase 1: Harvest
It consists in the grape harvest. When it is time to harvest depends on the degree of ripeness desired for the grapes, which varies according to the grape variety, and the product to be obtained. The longer the grapes remain on the plant, the higher the sugar and pigmenting substances content in the musts and the lower their acidity. But the grapes must be preserved from birds, lizards and ants. Sometimes it is decided to proceed with the harvest also to prevent the berries from being eaten by these animals. This year, for example, the harvest of most of our grapes took place on August 19th, earlier than in other years. This is also because this year we have not put any product on the vines which for this reason will be easy prey for animals and pathogens.
Phase 2: Destemming and pressing
The berries are separated from the Raspi. The stalks contain high quantities of tannins, lignin, resins that are better to avoid being transferred to the wine. The grapes are then pressed, which we carry out with our hands, as the quantity of grapes to be processed is limited.
The pressing of the berries is used to separate the grape juice from the pomace (skins and seeds). Grape juice represents must.
Phase 3: Alcoholic fermentation
Among the different stages of wine preparation, fermentation is the most important.
Fermentation is a natural process by which the must is transformed into wine.
It is a chain reaction of chemical phenomena through which the sugar contained in the grapes is converted, by yeast enzymes, into ethyl alcohol and carbon dioxide.
We only use the natural yeast present on the skins, without adding anything else.
Depending on the type of yeast, about 50% of alcohol, 45% of carbon dioxide, 3% of glycerol and 2% of other by-products are obtained from the conversion of sugar. These "by-products" play a decisive role in terms of the aromatic and gustatory qualities of the wine.
The skins are macerated with the must. In fact, the skins are indispensable, both for the large presence of polyphenols, both because they are necessary for the coloring of the wine, and to provide a certain tannic percentage of the wine.
Fermentation pushes the skins up, what is called the "hat" is formed.
At least once a day then it is necessary to “break the hat”, that is to lower the skins so as to continue the contact between the skins and the liquid part. This operation is called fulling.
Fulling is very important as the pomace, in contact with oxygen, oxidizes and is attacked by acetic bacteria which transform ethyl alcohol into acetic acid. Therefore, by "breaking the cap" and dipping the marc in the must twice a day, an excessive exposure to air and oxygen of the marc is avoided, which, remaining moist, do not oxidize and therefore acetify.
It is necessary that the skins are in contact with the must as they contain the yeast necessary to favor fermentation and therefore the transformation of sugars into ethyl alcohol and carbon dioxide, they also give the wine a certain aroma and the necessary color.
For red wine, the must ferments for a period that generally ranges from 7 to 10 days
Phase 4: Racking
The flower of the wine is separated from the solid parts (pomace). Before racking, the sugar content of the must must be measured. The measurement can be done through a Mostimeter. Generally we draw off when the sugar content is around 1 - 2%.
The racking this year was done 7 days after squeezing.
The previous day Nonno Gigino no longer lowered the skins, to allow only the wine to remain on the bottom.
After racking in the container, the pomace remains and this time it is not pressed. This pomace was used as a fertilizer
#wine
#vintage
#alcoholic fermentation
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