The answer is, well, kinda. Icing sugar doesn't really go off in the classical sense, like milk or eggs might. But, over time, it can still become less effective or even develop some unwanted issues. For example, if it's exposed to moisture, it can start to clump or become lumpy, which is definitely not what you want when you're trying to whip up a smooth frosting.
Think of icing sugar like a super-fine powder that's just begging to absorb any moisture it comes into contact with. It's like a sponge, but instead of soaking up water, it's soaking up the air's humidity, which can cause it to become stale or musty. Not exactly what you want in your baked goods, right?
Now, you might be wondering, how can I prevent my icing sugar from going bad? Well, it's actually pretty simple. Just store it in an airtight container, like a jar or a ziplock bag, and keep it in a cool, dry place. Easy peasy, right?
Can Icing Sugar Go Bad, And Should You Use An Expired One?
