Yeast moves in the range of 5℃ ~ 40℃, stops moving below 4℃ and dies above 60℃, and the most active temperature is 35 ~ 40℃. Ensuring proper temperature and humidity is the key to success. The optimum environmental temperature for fermentation is between 30-35 degrees, preferably not more than 40 degrees. The humidity is between 70-75%. The environment under this data is the most favorable for dough fermentation. Generally speaking, yeast cells cannot grow below the freezing point of water or above 47℃. The temperature of the freezing room is between-1- 10 degrees, and the yeast will move slowly even if it doesn't stop moving, so of course the dough can't be fermented.