Powdered sugar, also known as confectioners’ sugar, is granulated sugar that has been ground up into a powder form and combined with corn starch.
Popular in baking, powdered sugar is useful when making fudge, creating homemade frosting, and dusting over a brownie or a stack of pancakes.
Using powdered sugar to whip up homemade icing can take your sweet treat to the next level.
But as you’re digging through the cupboard searching for it, you think to yourself:
When did I buy this? Is it still good?
Often, powdered sugar is sold in large bags and used only for small parts of baking. This makes it an ingredient that sits in your cupboard for months without being put to use. It may only be brought out during the holidays or on a special occasion when you want baked goods.
But don’t worry. Today, we’re talking about how to store powdered sugar, how to tell if it’s gone bad, and how long you can expect powdered sugar to last.
How To Store Powdered Sugar

If the bag is unopened, then it can be stored for a couple of years. You can just leave the powdered sugar in its original packaging and store it in a cool, dry place where it will stay good until it is opened.
Once opened, it is important to note how long you think it will be until you use the powdered sugar again. Will it be a couple of months? Or a year?
If it will only be a couple of months, then a simple tight seal on the top should be enough to keep your powdered sugar safe until you need it again.
If you think it will be up to a year, then it is important to take some extra steps when packing up your powdered sugar.
Using a resealable bag or an airtight container will be your best bet when it comes to storing powdered sugar for a longer period of time.
One important thing to note: ensure that the airtight container you are transferring the sugar into is completely dry. Moisture can cause your powdered sugar to spoil.
By using a resealable bag or a container, you are ensuring that, by the next year, your powdered sugar will be ready to use while also being protected from dust, mold, or cupboard critters.
How Long Does Powdered Sugar Last?

Your powdered sugar will basically be okay indefinitely, whether opened or unopened, as long as no moisture or bacteria has spread. That’s because it’s considered “shelf-stable,” meaning it’s been deemed non-perishable at room temperature by the USDA.
However, to get the most out of your sugar, in terms of flavor and texture, you should use your powdered sugar within two years.
By ensuring you do not exceed the 2-year mark, you will always have fresh powdered sugar to use for baking.
Signs You May Need To Replace Your Powdered Sugar

If your powdered sugar has not been stored properly, then there is a chance that you may need to replace the bag currently in your cupboard.
Here are signs to look for to tell if your powdered sugar has gone bad:
- Discoloration: If the sugar does not look like the typical white that it should be, then there is a chance it has gone bad.
- Lumps: While small lumps are common, hard lumps can be an indication that too much moisture has hit your powdered sugar and has not been sealed properly. If the lumps are hard and cannot be sifted, then it may be a sign that your powdered sugar needs to be replaced.
- Odor: When powdered sugar is not stored properly, it is easier for odors from your pantry to find their way into the container. This may not necessarily “spoil” your sugar, but it is definitely something that will affect the flavor of your sweet treat. That means your best bet is to just replace the powdered sugar to ensure the proper flavor for your desserts.
- Mold: If you see mold anywhere in the container, then you need to replace it immediately.
- Insects or eggs: If you have not stored your powdered sugar properly, then there is always a chance that cupboard critters can make their way into your powdered sugar. Any sign of a bug or egg, toss the powdered sugar immediately and replace it.
The Bottom Line
If stored properly, powdered sugar has a shelf life of up to 2 years. It is important to store your powdered sugar properly after it has been opened to ensure you will get two years of use out of it. Using an airtight container is in your best interest and can help maintain the freshness of the powdered sugar you are storing.
Remember, small lumps that can easily be sifted are common, but do not mistake them for hard lumps that indicate too much moisture coming into contact with your powdered sugar.
If it has been a while since you last needed the powdered sugar sitting in your pantry, you may want to look over the list of signs it needs to be replaced to see if it has gone bad. Examine the powdered sugar for any of the signs listed and ensure that it does not have any of the characteristics of spoiled powdered sugar.