Fermentation process: It is beneficial to prevent the propagation of harmful bacteria to start fermentation as soon as possible after bottling grapes, so it is necessary to control the temperature after bottling to avoid too low temperature. Bubble rising and grape skin floating are the manifestations of the beginning of fermentation. Pay attention to the fact that a large amount of CO2 gas will be produced during the fermentation process, and strong sealing is prone to danger, so it should be properly ventilated. Stirring 1-3 times a day will make the grape skin contact with the juice as much as possible, and soak out the effective substances such as pigment and tannin on the skin. The normal fermentation period is about 1 week. During this period, there is no need to keep a small amount of ventilation, and the fermentation is completed without obvious bubbles. At this time, the grapes have successfully turned into wine, and the next process is to make the wine soft, sour and clear.

Fermentation temperature: The suitable fermentation temperature for red wine is 25-30 degrees, and that for white wine is 18-20 degrees.