The course of the second phase: silent fermentation.
The turbulent fermentation turns into silent fermentation imperceptibly. Yeast cells do not find food, they begin to feed on the substance of their own organism, until they finally die and sink to the bottom (a yeast sediment is formed); They are also prevented from reproducing by their own metabolic product – alcohol – and then they also sink to the bottom.
The wine needs to be monitored more closely during this phase, take samples and draw conclusions about the digestion progress based on the amount of sludge. The brighter and clearer the liquid becomes, the less yeast activity. You can tell by the taste, is there still any sugar, which can be fermented (with not very sweetened wine). For the sake of checking, the weight of the must is measured. The wine is considered fermented, when the liquid level in the test tube is at the "0" scale (or above, at the negative level).
To be sure, the yeast sediment must be touched again, to stimulate him to be active. If the water in the fermentation tube is moving, means, that the yeast is still not completely dead. Only when no pressure is exerted on the water in the tube all day or when the lid stops floating on the plastic hydraulic seal, means, that the second phase of fermentation is over and the time for the first dressing is approaching.
• Fermentation is complete, when the carbon dioxide stops escaping from the vessel and when Ochsle's glucosimeter shows 0 °. If the reading is negative, that also means, that the wine has fermented, because the alcohol contained in the wine (ok. 10% total quantity) it is lighter than water, and hence, the specific gravity of the wine is less than the specific gravity of water.