Can I open and partially use an active-dried yeast culture and reuse the balance at a later date?
A dried yeast culture will begin to absorb moisture as soon as it is opened. This can trigger the yeast to reactivate. If no must or nutrients are available the yeast die or become weakened. An open container also becomes a rich media for possible microbiological growth. It is recommended to close a container tightly immediately after opening. The balance should be used within a short period of time (1-2 weeks).