The extraction (english version)

We do the operation of extraction in winery after the fermentations.
First is the alcoholic fermentation: the grape juice is becoming wine thanks to the yeasts.
Then malolactic fermentation during witch bacteria are eating malic acid (a "strong" acid also present in apple juice, especially the Granny Smith) to transform it in lactic acid (the acid of milk, much rounder).                                                                          

Therefore, the wine is finished and must be separate from the lees, thin particles (yeasts, bacteria, etc.) fallen to the bottom of tank.

Let them in touch with wine could give bad tastes.
We perform a pomping a few centimeters above the bottom of the tank not to aspire the lees.
Then they will be sent to distillery.

You can see some "crystals of tartar" on the wall of the tank.
The wine, very rich in tartaric acid, releases these crystals during winemaking.
We call them "Vinpierre", literally "Stone of Wine".
But that is another story...