Even unopened yeast can go bad if it's not stored under the proper conditions. Here's how to keep that yeast lasting as long as possible.

By Sarra Sedghi
April 08, 2021

Did you stash up on a bunch of yeast during the great pandemic baking craze of 2020 before it all sold out? Or, are you a frequent baker or pizza maker who just wants to keep your product in the best possible condition? We're here for you.

Nothing will ruin your dough faster than dead yeast, and if you aren't storing yeast properly, it's likely to expire. Read on to find out how and why yeast goes bad and how to keep yeast fresher longer.

Does Yeast Expire?

Yeast is a living thing, which means that all yeast expires at some point. All yeast has an expiration date, but yeast will expire sooner if not stored properly. Properly stored yeast may last for up to four months beyond the expiration date. Improperly stored yeast may not make it to its expiration date.

How to tell if yeast is expired

The best way to determine whether your yeast is still kicking is to proof it. For proofing, you'll need to combine your yeast with 1/4 cup lukewarm water and 1 teaspoon of sugar, and let it sit for 10 minutes.

Yeast that's still good will bubble up. If there's no action whatsoever, throw the yeast out. You can use fresh proofed yeast as normal; just adjust the recipe to account for the added water and sugar.

Directly above shot of yeast in packet on white table

What Temperature Kills Yeast?

Yeast dies at 140 degrees F (60 degrees C). However, 120 degrees F is considered the injury point, so it's best to proof or activate yeast in water that's between 100 and 120 degrees F (38 and 49 degrees C).

How to Store Yeast

Active dry yeast

Theoretically, unopened active dry yeast will last for up to two years after the date it was packaged. Active dry yeast that's close to or past its expiration date should be proofed, because knowing before your bake is much better than watching your loaf of bread completely flop. Store opened active dry yeast in an airtight container in either the fridge or freezer.

Instant yeast

Like active dry yeast, instant yeast has a shelf life of two years and performs best when it's kept away from heat and moisture. After it's been opened, you'll need to seal it in an airtight container and store it in the fridge or freezer.

Fresh yeast

Fresh yeast typically lasts for two weeks in the refrigerator and up to three months in the freezer. If your fresh yeast has become dark brown, hard, or crusty, it's passed its prime, and if there's any mold, throw it out.

Here's a handy chart so you know exactly where to store yeast and for how long:

Type of Yeast: Active Dry & Instant Yeast Fresh Yeast


Cool, dark place


Shelf Life

2 years (unopened)
4 months (opened, refrigerator)
6 months (opened, freezer)

2 weeks (refrigerator)
3 months (freezer)

Can You Freeze Yeast?

Yes, you can store yeast in the freezer, whether it is opened or unopened. Once opened, be sure to store in an airtight container in the freezer for up to six months. Fresh yeast can also be frozen for up to six months.

You do not need to thaw dry yeast first — you can use your yeast straight from the freezer, but be sure to proof it first before using in your recipe. For fresh yeast, you should thaw the yeast overnight in the fridge before using; never thaw at room temperature. Once thawed, proof the yeast before using in your recipe.