The opened yeast can be stored for 2-3 months at most, provided that the yeast powder is put in a dry and cool place after being opened and can be stored for 2-3 months. The shelf life of unopened dry yeast is two years, and it only needs to be stored in vacuum at room temperature. This yeast is widely used in China. However, wet yeast can only be stored for 15 days and needs to be stored at a low temperature of 4-6 degrees.