Active Fermentation Extraction
The main event. Once yeast wakes up and starts converting sugar to alcohol, extraction shifts gear. Alcohol pulls out tannins much more aggressively than water. CO₂ rises through the wine, pushing the skins up to form a thick layer at the top — the “cap.”
The winemaker has to keep that cap wet with juice, or extraction stops. Two main techniques: punching down (pigeage) — physically pushing the cap down into the juice, several times a day, traditional and gentle; and pumping over (remontage) — pumping juice from the bottom of the tank up over the cap, faster and more aggressive.
Most Argentine winemakers do both during a single fermentation — gentle pump-overs early, gentle punch-downs later. The choice is everything: too aggressive and the wine becomes bitter; too gentle and it's thin.
