Hehe, why don't you tell me how many Jin of grapes you have brewed, and I'll tell you to put less sugar? If a month is too long, as upstairs said ... mold often grows. The fermentation process of wine takes about a week (18-25 degrees Celsius), depending on the local temperature, it may be completed in 3-4 days in high temperature areas, subject to the fact that all grape skins float up without bubbles. Take a week as an example, you must add sugar for the first time 24 hours after pressing (grape weight and sugar ratio are 13% to 8%).