Does Yeast Expire?
Yes, yeast expires and loses activity over time. Unopened dry yeast lasts 2 years in the pantry or up to 4 years frozen. Once opened, use within 4-6 months. Always proof yeast before baking to verify it is still active - dead yeast will not make dough rise.
Key Takeaways
- Yeast is a living organism that becomes less active over time and eventually dies.
- Instant yeast generally lasts slightly longer than active dry yeast.
- Fresh cake yeast has a much shorter shelf life (about 2 weeks refrigerated) and cannot be frozen.
Explanation
Yeast is a living organism that becomes less active over time and eventually dies. Both active dry yeast and instant yeast have expiration dates that indicate when potency begins to decline. Using expired yeast can result in bread that fails to rise.
To test (proof) yeast, dissolve 1 teaspoon in 1/4 cup warm water (100-110°F) with a pinch of sugar. Active yeast will foam and bubble within 10 minutes. If nothing happens, the yeast is dead and should be discarded.
Store unopened yeast in a cool, dry place. Once opened, transfer to an airtight container and refrigerate or freeze. Frozen yeast maintains potency much longer than refrigerated. Let frozen yeast come to room temperature before using.
Things to Know
- Instant yeast generally lasts slightly longer than active dry yeast.
- Fresh cake yeast has a much shorter shelf life (about 2 weeks refrigerated) and cannot be frozen.
- Yeast exposed to temperatures above 120°F will die immediately.