1. Before use, dry yeast should be rehydrated and activated to make yeast emulsion, so as to restore the normal function of yeast cells.
2. The dry yeast was put into warm water at 36-38 ℃ for 15-20 minutes at a ratio of 1:10-20, or was rehydrated in 2-4% sugar water for 30-90 minutes to make yeast emulsion, which could be added to fermented grains for fermentation.
3. Rehydration should be activated with clean water to prevent infection with miscellaneous bacteria.