Can dry yeast go bad? (+3 step yeast freshness test)

In this article, we will answer the question “Can dry yeast go bad?”, and how to tell If the yeast is still potent?

Can dry yeast go bad?

Yes, dry yeast can go bad. It usually comes with a best before date instead of a use-by date or expiration date. If stored correctly, dry yeast stays fresh 2-4 months past its best by date.

In the refrigeratorIn the freezer
Past printed datePast printed date
Dry active yeast(unopened)2-4 months4 months
Cake yeast(unopened)1-2 weeks2-3 months
Dry active yeast(opened)4-6 months6 months
Cake yeast(opened)4 monthsNot recommended

Does yeast go bad? 

Yes, yeast becomes inactive as time progresses. It is always recommended to check the expiration date before using the yeast in a recipe, because even if it doesn’t go bad, it may take longer to grow itself and make the bread rise.

How to tell if the yeast has gone bad?

If the yeast starts to clump together and/or appears discolored, discard the yeast immediately. In case of any apparent discoloration and mold growth, it is recommended to toss the yeast in the bin.

If the yeast looks and smells fine but is past its best before, better perform the freshness test before adding it to your dough.

How to store yeast?

There are two types of yeast that are used frequently by home bakers and commercial bakeries namely:

Dry yeast is quite shelf-stable due to which an unopened packet of dry yeast will be good in the pantry if kept away from stove heat, direct sunlight, and moisture. As soon as you open the packet, the dormant yeast granules become vulnerable to spoilage. Therefore, it needs to be refrigerated.

You cannot refrigerate dry yeast in an open packet. The humid environment of the fridge will destroy the quality of yeast. To overcome this, transfer the yeast to a zip-locked freezer bag and store it.

Fresh yeast, also called cake or compressed yeast is more susceptible to spoilage. It is sold in refrigerated form and must be stored in the refrigerator to keep it alive.

Can I use expired yeast?

You can use expired yeast but it may not be as potent as fresh yeast. When the yeast is dead, it cannot ferment your dough. Fortunately, there are ways you can tell if the yeast is still active or not. Rea don If you want to know how to perform a yeast freshness test.

Other FAQs about Yeast which you may be interested in.

How many teaspoons is 25 oz of yeast?

How to tell if yeast is still potent?

You cannot tell by looking at the yeast if it is dead or not. Perform the test below to check if the yeast is active.

  1. In a cup, take ¼ cup lukewarm water. It is best to check the temperature of the water using a thermometer and make sure it lies between 110-115°F. A temperature higher than 120°F will destroy your yeast. 

A temperature lower than 110°F will not be able to activate the yeast to its full potential. To the water, add 1 ¼ tsp of yeast and 1 tsp of granulated sugar.

  1. Give it a stir until yeast is dissolved completely. Wait for 10-15 minutes.
  1. If the yeast forms bubbles or foam on the surface and you smell a strong yeasty aroma, the yeast is active. If not, the yeast is dead.

This proofing test can also be performed with a small amount(walnut-sized) dough. 

How to proof dry active yeast?

  1. In a bowl, add 1/2 cup of warm (105° to 115°F) water, 1 tsp sugar, ¼ ounce yeast. Stir and wait for 10 minutes.
  2. If the mixture becomes foamy, the yeast is active.

How to proof cake yeast?

  1. In a bowl, add 1/2 cup of warm liquid (90° and 100°F) and 1 tsp of sugar.
  2. Stir the crumbled cake yeast into the mixture to dissolve it.
  3. After 10 minutes, if the liquid gives off a yeasty smell and becomes foamy on top, it is active. If not, it is dead.

The function of Yeast in baking

Yeast is a fungus that consists of a single cell. As the baking powder, it also acts as a leavening agent in baking. But the process through which it produces carbon-di-oxide is biological. The biological reaction, called fermentation, uses the starch in bread and ferments it to gas, alcohol, and water.

The alcohol evaporates during baking but helps develop gluten and add a lot of flavor to the bread, unlike baking powder. The gas produce helps raise the bread.


In this article, we answered the question “Can dry yeast go bad?”, and how to tell If the yeast is still potent?