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Can Powdered Sugar Go Bad?

If you don’t use powdered sugar all that often, finding a bag that’s a couple of months (or years) past its date isn’t anything unusual.

What do you do when you find such a package, though?

Do you discard it, or use it as if nothing happened? Can confectioner’s sugar actually go bad and how long does it really keep for?

If you’d like to learn a bit more about those topics, this article is for you. Read on.

Powdered sugar on a pancake - closeup
Powdered sugar on a pancake – closeup

Can Powdered Sugar Go Bad? How To Tell If Powdered Sugar Is Bad?

As you’ll learn in the next section, powdered sugar lasts pretty much indefinitely. But that doesn’t mean it can’t go bad.

If you don’t store it properly and get a bit unlucky, it can go off.

Here are the signs that your powdered sugar is spoiled:

  • Mold in the package. Please don’t try to scoop the moldy part and use the rest, just get rid of it altogether.
  • Insects, bugs, or eggs in the bag. If you find any pantry pests, dead or alive, throw it out.
  • The powder smells off. Powdered products easily pick us smells. While smelly confectioner’s sugar isn’t technically spoiled, you don’t want to dust your pancakes with it.

Small clumps of confectioner’s sugar is nothing to worry about. Just sift the powder while dusting the food and problem solved.

Powdered sugar instead of granulated sugar in pancake batter
Powdered sugar instead of granulated sugar in pancake batter

How Long Does Powdered Sugar Last?

For starters, you need to know what powdered sugar consists of.

Powdered sugar (or confectioner’s sugar) is a type of finely grounded sugar mixed with cornstarch. The cornstarch gives the sweetener its characteristic fine, powdery consistency.

As you may or may not know, cornstarch lasts pretty much indefinitely, just like table sugar. And the mix lasts pretty much indefinitely too.

Pancakes with powdered sugar
Pancakes with powdered sugar

That means it’s okay to use “expired” powdered sugar, and you don’t need to worry about the date on the label. Opening the bag or package doesn’t change much either.

Sure, over time some small clumps may form, but as you already know those are expected and perfectly normal.

Knowing that, it’s time to talk about storing powdered sugar, so that yours never spoils.

Powdered sugar in a bag
Powdered sugar in a bag

How to Store Powdered Sugar?

The best way to store powdered sugar is to keep it in the pantry at room temperature, away from moisture and any odors.

For unopened containers of powdered sugar, there’s no need for any fancy containers or anything like that. The original package will do just fine, even for long term storage.

Once you open the bag, consider how long it will take you to finish it.

If “a couple of months tops” is what comes to mind, simply wrapping the bag is usually good enough. That is assuming that you don’t have issues with pantry pests.

If every now and then you find larvae or bugs in your dry foods in the pantry, make sure powdered sugar is always sealed tightly.

Just baked cheese buns dusted with powdered sugar
Just baked cheese buns dusted with powdered sugar

If you know that the mentioned package needs to keep for a year or longer, spending an extra minute or two on packaging is well worth the effort.

An airtight container or a resealable bag both work really well for storing dry goods, and I recommend using one of them.

Before transferring the sugar, make sure the bag or container is perfectly dry on the inside. That’s especially important if you took it right from the dish drying rack.

Pancakes topped with powdered sugar
Pancakes topped with powdered sugar


  • Powdered sugar lasts pretty much indefinitely.
  • Throw out the bag if you notice any signs of mold, pantry pests, or the powder smells off.
  • Keep confectioner’s sugar at room temperature, in a sealed bag or container, away from moisture and strong smells.