Prepared must must be fermented in vessels almost full of it. Cover the ridge with a suppository made of pure cotton wool. After the turbulent fermentation has ceased, the cotton wool is replaced with a tight stopper equipped with a fermentation tube. The cork is covered with paraffin. Water with the addition of glycerin or alcohol is poured into the tube. In the absence of a tube, pour the must in the neck with paraffin oil or pure olive oil to a height of one centimeter. With the latter method, the shortage in the ridge tile should be supplemented from time to time by adding clean water. These treatments are aimed at closing the air flow to the must (otherwise there will be vinegar instead of wine), and at the same time allowing the gas to escape, produced during fermentation, which can easily pass through a pipe or oil (with 10 liters of must form approx 500 liters of gas).
The best temperature for fermentation is 17-22 ° C, thus room temperature. Above 25 ° C., fermentation goes more quickly, but with a loss of the aromatic constituents of the must.
After a couple of weeks, when the must has stopped fermenting, t. j. as soon as a small amount of bubbles came out and the liquid from the top began to clear, the fermented must should be pulled from above the sediment to the ridge tile with a rubber tube. (Necessary surgery, because the yeast sediment will spoil the wine by its decomposition). Instead of a gander, better to use a barrel, where wine matures faster and better. So that the vessel is always full, the missing must must be supplemented with another wine, or add unsugarated pure water (possibly sprinkle clean flint or glass beads). Then close the vessel, as previously, with oil or fermentation tube.