Got a packet or container of “expired” dry yeast, and not sure if you can still use it? Does dry yeast expire?
Or you bought a block of fresh yeast, and it’s nearing its date. How long does fresh yeast last, exactly?
Yeast can be confusing, especially if you’re not an experienced baker.
There’s active dry yeast, instant (or quick rise) yeast, and fresh yeast (sometimes called baker’s yeast). And each one works slightly differently.
In this guide, I walk you over the basics of storage, shelf life, proofing (or activating), and the expiration of yeast.
I divided the article into two large sections.
The first is about granulated dry yeast. If you have active dry yeast or instant yeast on hand, that’s what you’re looking for.
The second one is about fresh yeast – those small blocks you buy in the refrigerated section.
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)
Both look similar, but there are some key differences you should be aware of. I discuss those in the very 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, while the latter doesn’t. This way, using instant yeast reduces the time needed for your dough to rise before it’s ready for cooking.
Both types of dry yeast are interchangeable – you can use instant yeast if your recipe calls for active dry yeast and the other way around.
The only thing to remember is to proof active dry yeast if you’re substituting it for the instant variety.
The rest, like the shelf life, storage practices, and expiration, are pretty much the same no matter which variety you have.
How Long Does Dry Yeast Last? Does It Expire?
Dry yeast (both active and instant) comes with a shelf life of 1 to 2 years, noted by the best-by date on the label. And it keeps for an extra 1 to 3 months past the “expiration” date.
If you buy dry yeast in a container (instead of small packets), refrigerate it after opening and use it within 4 months. Or freeze for up to half a year.
Of course, these aren’t hard and fast rules – sometimes, your yeast might retain potency for longer. Other times, if you’re unlucky or don’t follow proper storage practices, it might go bad sooner.
Can you use expired dry yeast, then?
Yes, as long as it activates properly, and it’s not like a year or more past its date. I mean, dry yeast that’s “expired” for more than a year probably wouldn’t activate anyway.
What about instant yeast?
While you don’t have to activate it before using it, that doesn’t mean you can’t. And if your instant yeast is past its date, I suggest proofing it to make sure it’s still active. Otherwise, you might end up with a flat and dense loaf of bread.
That said, in some circumstances, you should discard dry yeast. Those include:
- the granules are clumping or forming solid chunks
- any signs of water or any organic growth (e.g., mold) in the package
How To Store Dry Yeast
Store unopened dry yeast (both active dry and instant) in a cool and dry place, like a cupboard in the kitchen. The fridge and the freezer are viable options too, but not really necessary.
Once you open the package, refrigerate or freeze the leftover dry yeast.
If you’re buying dry yeast in those small single-serving packets, you can simply store them where you keep your spices.
But if you use dry yeast regularly, going with a large container instead of dozens of packets is probably a better approach. If that’s what you do, remember to:
- Seal 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 all the extra air.
- Place the sealed bag in the fridge or freezer.
Make sure your dry yeast is at room temperature before using it. If you pull it from the fridge or freezer, allow the granules to sit on the counter for at least half an hour before using.
Can You Freeze Dry Yeast?
Yes, you can freeze dry yeast. In fact, that’s one of the recommended ways of storing it after first opening the container.
There’s no special process for freezing dry yeast. You just need to seal the granules tightly (possibly in a bag) and throw them in the freezer.
Before using the yeast, give it at least 30 minutes on the counter before using it. This way, it will reach room temperature, and will be able to activate again.
How long can you freeze dry yeast?
Red Star Yeast suggests using it within 6 months of freezing. It might help if you label the bag with the freezing date so that you know what you’re working with when you pull it out.
The 6 months period is just a general, fairly safe suggestion. If yours sits in the freezer for longer, chances are it’ll still work okay. Again, proof it (even if it’s the instant variety) to be safe.
Proofing Dry Yeast
Checking yeast effectiveness (or proofing the yeast) is pretty similar for both dry and fresh yeast. You only need some warm water and sugar to do it.
Prepare the following:
- 1/4 cup of warm water. If you have a kitchen thermometer, go with 105° to 115°F or 40° to 46°C, which is ideal for the yeast to grow. Otherwise, use warm but not hot water. If your recipe doesn’t use water, use whatever liquid it calls for instead (e.g., milk).
- 1 packet of dry yeast or 2 1/4 teaspoons
- teaspoon of sugar
If your liquid is hotter than 140°F or 60°C, it will destroy the yeast.
- add the sugar to the water and give it a stir
- add the dry yeast and mix everything well
- leave the mixture for at least 10 minutes in a warm spot
It takes between 5 to 10 minutes for dry yeast to activate. If you leave it in a cool spot, it might need even more.
If it’s the middle of winter and your room temperature is on the colder side, consider warming up your oven for like 3 to 4 minutes on low, and proofing the yeast there.
You know that your yeast is activated if it foams up to about 1/2 cup mark. If there’s no foam or froth on top, it’s not potent enough to use. If there’s only a little, give the mixture a couple of minutes more, especially if it doesn’t sit in a warm spot.
Remember to deduct the sugar and water from the recipe to adjust for the ingredients you used for proofing.
Many recipes using dry active yeast have the proofing step built-in. Sometimes, besides the sugar and liquid, the recipe will ask you to add a couple of tablespoons of flour to help activate the yeast. That’s pretty common and works just as well.
Last but not least, you can activate this way both active dry yeast and instant yeast. For the latter, it only makes sense when you’re working with old yeast that you’re not sure is still potent.
Fresh (or cake) yeast isn’t as popular as dry yeast because it has a much shorter shelf life than the latter, and honestly, is a bit of a pain to work with.
But it also tends to produce better baked goods, and many bakers swear by it.
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 issue in mind, use this navigation:
How Long Does Fresh Yeast Last?
Fresh yeast is a living organism that stays active (and therefore potent) for about 2 to 3 weeks after production, noted by the use-by date on the label.
Unlike dry yeast, fresh yeast doesn’t start potent for much longer past the date on the table. Sure, you can get a couple of days, sometimes maybe a week, but that’s it. Obviously, just as well your fresh yeast might become inactive even earlier.
If you know you won’t be able to use the rest of the package, freezing fresh yeast is a good solution to that problem.
How To Tell If Fresh Yeast Is Bad?
Throw out fresh yeast that’s:
- starts to grow mold
- smells off or moldy
If your fresh yeast looks and smells okay, and isn’t more than a couple of days past its date, chances are it’s okay to use. Make sure to proof it before you commit all your ingredients, though.
How To Store Fresh Yeast
Fresh yeast is available in the refrigerated section, and you should keep it in the fridge at all times.
When you need it, cut off as much as the recipe calls for and put the rest back in the refrigerator.
Also, make sure it’s wrapped properly. Otherwise, it will dry out after only a couple of days of opening the package for the first time.
Can You Freeze Fresh Yeast?
Yes, you can freeze fresh yeast, and it freezes really well for at least 5 months. I know because I actually tested it.
All you need to do is to cut the block into serving-size portions, wrap each one with aluminum foil, and freeze it.
Here’s my article on freezing fresh yeast, if you want to learn more or check how I tested freezing fresh yeast.
Proofing (Activating) Fresh Yeast
By proofing the yeast, you make sure that the dough you will prepare will turn from this (just mixed dough for my bread rolls):
to this (same dough after rising for 90 minutes):
For fresh yeast, many recipes have the proofing process built-in, 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 for 10 minutes.
After 10 minutes, you should notice a lot of foam.
If that’s not the case, discard the yeast. If there’s a ton of foam, you can add the rest of the ingredients needed, and go from there.
Please remember to decrease the amount of liquid added by half a cup and add one less teaspoon of sugar, since those are already added.