How long does yeast last?
Do you have a packet or container of “expired” dry yeast and aren’t sure if you can still use it? Does dry yeast expire?
Or you have bought a block of fresh yeast, and its due date is approaching. How long exactly does fresh yeast last?
Yeast can be confusing, especially if you’re not an experienced baker.
There’s active dry yeast, instant (or quick-rising) yeast, and fresh yeast (sometimes called baker’s yeast). And each one works slightly differently.
In this guide, I’ll walk you through the basics of yeast storage, shelf life, proofing (or activation), and expiration.
I have divided the article into two large sections.
The first deals with granulated dry yeast. If you have active dry yeast or instant yeast on hand, that’s what you’re looking for.
The second is about fresh yeast, those little blocks you buy in the refrigerated section.
Dry yeast
Dry yeast comes in the form of dehydrated granules.
There are two options available on the market
- active dry yeast
- instant yeast (or quick rise yeast)
They both look similar, but there are some key differences that you should be aware of. I discuss them in the next section.
If you have a specific question in mind, use this navigation:
Active dry yeast vs instant yeast
The main difference between active and instant yeast is that the former needs to be activated (or proofed) before using it, while the latter does not. In this way, the use of instant yeast reduces the time required for the dough to rise before it is ready to cook.
Both types of dry yeast are interchangeable: you can use instant yeast if your recipe calls for active dry yeast, and vice versa.
The only thing to remember is that you should try active dry yeast if you are substituting for the instant variety.
The rest, like shelf life, storage practices, and expiration, are pretty much the same no matter what variety you have.
How long does dry yeast last? Does it expire?
Dry yeast (both active and instant) has a shelf life of 1-2 years, indicated by the expiration date on the label. And it keeps for an additional 1-3 months after the “expiration” date.
If you buy dry yeast in a container (rather than small packets), refrigerate after opening and use within 4 months. Or freeze up to half a year.
Of course, these are not hard and fast rules: sometimes your yeast can retain its potency for longer. Other times, if you’re unlucky or don’t follow proper storage practices, it can spoil sooner.
So, can you use expired dry yeast?
Yes, as long as it is activated correctly and a year or more has not passed since its date. I mean, dry yeast “expired” more than a year ago probably wouldn’t kick in anyway.
And the instant yeast?
Although you don’t have to activate it before using it, that doesn’t mean you can’t. And if your instant yeast is expired, I advise you to test it to make sure it’s still active. Otherwise, you could end up with a flat, dense loaf of bread (here’s the length of the bread).
That being said, in some circumstances, you should rule out dry yeast. They are between them
- granules clump together or form solid pieces
- any signs of water or any organic growth (eg mold) on the container
How to store dry yeast
Store unopened dry yeast (both active dry and instant) in a cool, dry place, such as a kitchen cabinet. The fridge and freezer are also viable options, but not really necessary.
Once the package is opened, refrigerate or freeze any leftover dry yeast.
If you buy your dry yeast in those little single-serving packets, you can just store it where you keep your spices.
But if you use dry yeast regularly, it’s probably best to opt for one large container rather than dozens of packets. If that’s what you do, remember
- Seal the dry yeast tightly, and with as little air as possible. A freezer bag is a much better option than an airtight container, because you can squeeze out any excess air.
- Place the sealed bag in the refrigerator or freezer.
| ADVICE |
|---|
| Make sure your dry yeast is at room temperature before using it. If you take it out of the fridge or freezer, let the granules sit on the counter for at least half an hour before using it. |
Can dry yeast be frozen?
Yes, you can freeze dry yeast. In fact, it is one of the recommended ways to store it after opening the container for the first time.
There is no special process for freezing dried yeast. You just have to seal the granules well (possibly in a bag) and put them in the freezer.
Before using the yeast, leave it on the counter for at least 30 minutes before using it. In this way, it will reach room temperature and can be activated again.
How long can dry yeast be frozen?
Red Star Yeast suggests using within 6 months of freezing. It may help to label the bag with the freeze date so you know what you’re working with when you take it out.
The 6 month time frame is just a general suggestion and a pretty safe one. If yours stays in the freezer longer, chances are it’s still working fine. Again, test it (even if it’s the instant variety) to be sure.
Try the dry yeast
Checking the effectiveness of the yeast (or proofing the yeast) is pretty similar for dry and fresh yeast. You only need hot water and sugar to make it.
Prepare the following:
- 1/4 cup of lukewarm water. If you have a kitchen thermometer, use 105° to 115°F or 40° to 46°C, which is ideal for yeast to grow. Otherwise, use warm but not hot water. If your recipe doesn’t use water, use whatever liquid it calls for instead (for example, milk).
- 1 packet dry yeast or 2 1/4 teaspoons
- teaspoon of sugar
| WARNING |
|---|
| If your liquid is hotter than 140°F or 60°C, it will destroy the yeast. |
So
- add the sugar to the water and stir
- add dry yeast and mix well
- leave the mixture for at least 10 minutes in a warm place
Dry yeast takes 5-10 minutes to activate. If you leave it in a cool place, it may need even more.
If it’s the dead of winter and your room temperature is on the cold side, consider heating the oven for 3-4 minutes on low, and testing the yeast there.
You’ll know the yeast is activated if it foams up to the 1/2 cup mark. If there’s no foam on top, it’s not powerful enough to use. If there’s only a little, give the mixture a couple more minutes, especially if it’s not in a warm place.
| ADVICE |
|---|
| Remember to subtract sugar and water from the recipe to adjust the ingredients you used for fermentation. |
Many recipes that use active dry yeast have the fermentation step incorporated. Sometimes, in addition to the sugar and liquid, the recipe will call for you to add a couple tablespoons of flour to help activate the yeast. That’s pretty common and works just as well.
Last but not least, you can activate both active and instant dry yeast this way. In the case of the latter, it only makes sense when you’re working with old yeast that you’re not sure is still potent.
Fresh yeast
Fresh (or cake) yeast isn’t as popular as dry yeast because it has a much shorter shelf life than dry yeast and is honestly a bit of a pain to work with.
But it also tends to produce better baked goods, and is trusted by many bakers.
Below, I cover everything you need to know about storage, shelf life, freezing, and activating fresh (or baker’s) yeast. If you have a specific topic in mind, use this navigation:
How long does fresh yeast last?
Fresh yeast is a living organism that remains active (and therefore potent) for about 2-3 weeks after production, depending on the expiration date on the label.
Unlike dry yeast, fresh yeast does not stay potent much longer after the date listed on the table. Sure, you can have a couple of days, sometimes a week, but that’s about it. Of course, it’s also possible for your fresh yeast to go dormant even sooner.
If you know you won’t be able to use the rest of the packet, freezing fresh yeast is a good solution to that problem. Or, in many cases, you can bake what you were going to make and freeze it instead. Homemade cinnamon rolls are a good example.
How to know if fresh yeast is bad?
Throw away any fresh yeast that is
- be discolored
- has dried up
- mold starts to grow
- smells bad or is moldy
If your fresh yeast looks and smells good, and is no more than a couple of days past its expiration date, then you can most likely use it. However, be sure to taste it before putting all the ingredients in.
How to keep fresh yeast
Fresh yeast is available in the refrigerated section, and you should always keep it in the fridge.
When you need it, cut the amount called for in the recipe and store the rest in the fridge.
Also, make sure it’s well wrapped. Otherwise, it will dry out within a couple of days of first opening the package.
Can fresh yeast be frozen?
Yes, you can freeze fresh yeast, and it freezes very well for at least 5 months. I know because I’ve tried it.
All you have to do is cut the block into serving-size portions, wrap each one in aluminum foil, and freeze.
Here is my article on freezing fresh yeast, in case you want to know more or check out how I tried freezing fresh yeast.
Proof (activate) fresh yeast
By proofing the yeast, you make sure the dough you’re going to make turns out like this (freshly mixed dough for my rolls):
to this (same dough after rising for 90 minutes)
For fresh yeast, many recipes have the fermentation process incorporated, or you can do it yourself.
You start with half a cup of water or milk (90° and 100°F, or 32° to 38°C) and dissolve 1 teaspoon of sugar in it. Then you add the cake yeast, mix it well and leave it for 10 minutes.
After 10 minutes you should notice a lot of foam.
If not, discard the yeast. If there is a lot of foam, you can add the rest of the necessary ingredients, and go from there.
| INFO |
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| Remember to decrease the amount of liquid added by half a cup and add one less teaspoon of sugar, since these are already added. |