How long does yeast last?
Unopened, it keeps in the cupboard for about 1 year. Once opened, in the fridge for about 2 weeks.
This refers to: Dry yeast.

Shelf life of yeast at a glance
| Storage | Unopened | Opened |
|---|---|---|
| Cupboard | 1 year | – |
| Fridge | – | 2 weeks |
| Freezer | 6 months | – |
Fresh yeast belongs in the fridge and keeps at most about 2 weeks there, around 6 months frozen. Keep opened dry yeast sealed and cold and use it soon.
Past its date does not mean spoiled
These are guide values for food stored correctly. A best-before date is not a throw-away date: many products are still fine after it. Check how it looks, smells and tastes. Mould, an unusual smell or a bulging can are reasons to throw it away. A use-by date is different: do not eat the food after it.