Does Yeast Go Bad? How to Tell + Shelf Life (4 Months Fridge)

Opened Unopened

Per USDA FoodKeeper

On the counterCounter

Refrigerate

once opened

In the fridgeFridge

4 months

at or below 40°F (4°C)

In the freezerFreezer

6 months

at 0°F; quality, not safety

On the counterCounter

2 years

cool, dry place

In the fridgeFridge

Not needed

shelf-stable

In the freezerFreezer

6 months

at 0°F; quality, not safety

Quick answer

Yes. Yeast lasts 4 months in the fridge and 6 months in the freezer. After that, or sooner if stored badly, it spoils: watch for the signs below.

How to tell if yeast is bad

Smell

Musty, sour or rancid odour.

Texture

Clumping from moisture, or a damp feel.

Pests

Webbing, holes, or tiny insects in the bag.

Flavour

Flat, stale or bitter taste — quality is gone even if it is safe.

Yeast past the expiration date

Unopened

FoodKeeper gives unopened yeast 2 years in the pantry, counted from the day you buy it. "Best-by" and "sell-by" describe quality and stock rotation, not safety; only infant formula carries a federally required use-by date.

Opened

Once opened, the printed date no longer applies. Count 4 months in the fridge from the day you open it.

How to keep yeast fresh longer

Store in cool, dry place. Must be refrigerated or frozen once opened.
Store in an airtight container in a cool, dark, dry place.
Keep away from the stove and dishwasher, where heat and humidity speed spoilage.