Shelf Life of

How Long Does Yeast Last?



How long does yeast last? The shelf life of yeast depends on the best before date and how it is stored. Yeast is a leavening agent containing active enzymes that create CO2 (carbon dioxide) when moistened. It is the starting ingredient in almost all bread recipes and the majority of baked goods in general that need to rise before baking.

The best by date for yeast is two years after the date it was packaged. Red Star, for example, stamps their products with the month & year that is two years out from the manufacture date. For example, MAR 2014 08 09 – indicates that optimal results will be realized if the product is all used up by March of 2014 (the last 4 digits are for their own manufacturing purposes) [1].

Does yeast go bad? Yes, it does. So, how long does yeast last? When properly stored (see below), yeast shelf life beyond its best by date is …

Unopened Pantry Refrigerator
Past Printed Date Past Printed Date
Dry Active Yeast lasts for 2-4 Months 4 Months
Cake Yeast  lasts for 1-2 Weeks 2-3 Months
Once Opened – regardless of date Refrigerator Freezer
Dry Active Yeast lasts for 4-6 Months 6 Months
Compressed or Cake Yeast lasts for 4 Months Not recommended

But remember, yeast, like a lot of other baking products, usually has a best before date and not a use by date or expiration date. Because of this distinction, you may safely use yeast for your baking needs for a time after the best before date has lapsed.

How to tell if yeast is bad, rotten or spoiled?

Practicing proper hygiene and food safety discipline will help prevent food borne illness.
Yeast will eventually change from a light tannish grey to a darker brown color and begin to clump together when it is getting old. Once you see these changes, the yeast has gone bad. But before that, it will probably look fine but may or may not be alive and well. When it is going bad, the organisms are becoming less active and dying. So, older yeast will take longer to rise.
The best way to tell if yeast has gone bad is to perform the yeast freshness test below.

Yeast Freshness Test


Yeast Freshness Test

Follow these steps to test if your room temperature yeast is fresh:

1) Dissolve 1 teaspoon of granulated sugar in 1/2 cup warm (110°-115°F) tap water inside of a one cup or larger measuring cup.
NOTE: It is best to use a thermometer, but if you don’t have one make sure the tap water is warm, not hot, if touched. Water that is hotter than 120°F will kill the yeast and cool water will not be able to activate the yeast.

2) Stir in a yeast packet (or 2-1/4 tsp of dry yeast) until dissolved.

3) Wait – in a minutes, it should become activated and after 10 minutes should rise to the 1 cup mark.

4) Use your test in your recipe right away (remembering to deduct 1/2 cup liquid from your recipe) – OR, if it did not rise then your yeast has gone bad and should be thrown away.

How to store yeast to extend its shelf life?

Proper food storage is the key to extending the expiration date of food.
Yeast is a living organism which becomes less active over time, much like yogurt cultures. Like most foods, it perishes even quicker when exposed to air, moisture and/or heat.

Unopened packages should be stored in the cupboard or other cool, dry place (refrigerator is fine too but not necessary until it is opened).
Once the package or jar is opened, it must be refrigerated (or frozen) in an airtight container with as much air squeezed out as possible.

For a long term option, dry yeast can be frozen for about 6 months after opening.

Dry yeast should always be be brought to room temperature before using, so be sure to remove only the amount needed from the fridge or freezer about 30-40 minutes before using.

Cake Yeast (also called Compressed) is even more perishable than dry, requiring constant refrigeration below 45°F to maintain its freshness and activity. Always wrap remaining cake yeast tightly and store in an airtight container in the refrigerator.
We do not recommend freezing cake yeast. [1].

How long is yeast good for when prepared in a dish?

How long does yeast last? That depends. How long does flour last? In general, it expires along with the fastest expiring ingredient in the dish. To find out how long other ingredients are good for, please visit the Dairy, Drinks, Fruits, Grains, Proteins, Vegetables and Other sections of Eat By Date or search below!

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What are our shelf life resources?

Our research into the how long does yeast last question incorporates findings from multiple resources, including the United States Department of Agriculture and the United States Food & Drug Administration. In addition, we scoured the web for informative articles and reports related to food safety, food storage and shelf life.

*An important note about expiration dates …

Although the shelf life information on Eat By Date is generally reliable, please remember that environments vary and thus individual cases will vary so our advice should only be taken as an opinion and guide to the shelf life of foods. So, please eat responsibly!