After about three days, the fermentation gradually entered a vigorous period, and most of the skin dregs gathered in the upper layer. After a little stirring, white bubbles can be seen, which is normal. If the fermentation is vigorous, the miscellaneous bacteria will be suppressed. You can kill bacteria by sprinkling high-alcohol liquor on the top floor. Don't touch spirits with unclean tools. Cover it, but don't seal it. Wait two days to see the situation.