1. Reproduction speed: such as in the wort droplet culture for 24 hours, a las 12 yeast cells, you can produce 55 sub-cells;

2. Mash concentration: the general alcoholic yeast in the alcoholic mash containing 5 percent (capacity), the fermentation capacity is weakened. Fermentation ability will be weakened, when the alcohol concentration content in the mash reaches 12% (capacity), the fermentation will stop. Therefore, in production, the concentration of saccharification mash is often controlled between 15-18Bx, and the alcohol content of fermented mature mash is about 8-9% (capacity);

3. Cultivation Temperature: Lars 12 yeast propagation temperature is 30-33℃, the lowest is 5℃, the highest is 38℃. At the right temperature, the yeast reproduction speed up. If the temperature is too high or too low, it will affect the propagation of yeast cells, and even cause the senescence or death of yeast;

4. pH value: The pH value of fermentation mash is related to the redox potential, which in turn has a direct relationship with the respiration of yeast. Alcoholic yeast can reproduce in a pH 4.0-6.0 environment, and if the pH of the mash is lower than 3, the vitality of the yeast is greatly reduced.