Does Yeast Go Bad?

Yeast is a leavening or raising agent that contains active enzymes. Yeast is the most important ingredient in almost all bread recipes. Also, yeast is a starting ingredient in baking different goods that need to rise before baking. Probably all of us have a yeast packaging somewhere in the kitchen. But, have you ever wondered if yeast can go bad over time? Does yeast spoil quickly and how can we store it properly?

In this article you will get the answers to these questions. We will also discuss the shelf life of yeast and how to tell if the yeast has gone bad. Read on and find out.

What Is The Shelf Life of Yeast?

Yeast is actually a living organism that becomes less active over the time. Also, it is known that yeast perishes faster if it is exposed to air, heat or moisture. The shelf life of yeast depends primarly on the way of its storage. If stored properly, yeast can last about 6 months at room temperature or in the fridge.

If you store it in the freezer, it can stay fresh for up to a year. The best by date of the yeast is two years after the date of its packaging. Like other baking products, yeast also has a best before date, but yeast doesn’t have an expiration date or a use by date. Because of that, you can safely use yeast for baking even after its best before date.

How to Store Yeast Properly?

Unopened packages of yeast should be stored in a dry and cool place. We recommend you to store yeast in the cupboard. You can also keep yeast in the fridge but it is not necessary until yeast is opened. When you open the package or the jar of the yeast, you have to store it in the fridge. The yeast should be placed in an airtight container and the air should be squeezed out as much as possible. If you want to extend the shelf life of the yeast and store it for a longer period of time, you have to frozen it. This way, yeast will last 6 months after opening.

Also, you should know that dry yeast should always be at room temperature before using, so it is necessary to remove it from the fridge about 30 minutes before using. You don’t have to remove from the fridge the whole packaging of the yeast, but only the amount that you need.

On the other side, cake or compressed yeast requieres constant refrigeration  in order to keep its activity and freshness. After using, it is necessary to wrap the remaining cake yeast tightly and to store it in the fridge. It is not recommended to freeze a cake yeast.

How To Tell if Yeast Has Gone Bad?

It won’t be hard to notice if yeast has gone bad. When yeast goes bad, the organisms in it become less active and they are dying. You will notice that the color of yeast has changed from grey to darker brown. Also, when the yeast goes bad, we can see clumps in it. When you notice these changes, it means that yeast has gone bad. But, the best way to tell if the yeast has gone bad is to perform the test that will show the freshness of the yeast.

If you want to be sure that yeast is still good, just put a teaspoon of yeast in a cup of warm water with sugar. This way you will easily see if the yeast has gone bad. The yeast freshness test includes three steps and you can see them below.

  1. You have to dissolve one teaspoon of granulated sugar in a cup of warm tap water. It is recommended to use a thermometer, but if you don’t have it, you can use warm water. The water should not be hot, because it can kill the yeast when it is hotter than 120 F. On the other side, if the water is cool it is not able to activate the yeast. Because of that, be sure that the water you use is warm when touched.
  2. The second step is to stir in the water a teaspoon of yeast and to dissolve it.
  3. You should wait a minute and after approximately 10 minutes, the yeast will rise. If the yeast didn’t rise, it means that it has gone bad.


As you have seen, yeast goes bad after certain time. You should store it in an airtight container in a dry and cool place, until opened. When the container of yeast is opened, store it in the fridge.

If you buy larger amounts of yeast, it is best to store it in the freeze. Remember that spoiled food is related to many health risks. It is best to use the foods  before their shelf life expires.