You don’t need a chemistry degree to test icing sugar. If it’s still soft and pours like snow, congratulations—you’re good to go. But if you see hard lumps that look like ancient fossils, don’t panic. You can break them up by pressing the sugar through a fine-mesh sieve (a strainer works fine). If the lumps are rock-solid and refuse to crumble, that’s when you should toss it.
Can Icing Sugar Go Bad, And Should You Use An Expired One?
Also, smell it. Icing sugar is basically inert, so it shouldn’t have any odor. If it smells stale, musty, or like cardboard, get rid of it. That’s a sign the cornstarch has broken down, and your next batch of royal icing will taste like a dusty attic.
The Great Freezer Experiment
I’ve seen people online swearing you can freeze icing sugar to make it last forever. Let me save you the trouble: don’t do it. Freezing introduces condensation when you take it out, which turns your sugar into a sticky paste. I tried it once, and my bag ended up looking like a snow globe that got left in a rainstorm. Not cute.
Instead, if you buy in bulk, portion it into smaller bags and store them in a cool, dark cabinet. Use a marker to write the purchase date on the bag, so you don’t play guessing games later. Trust me, your future self will thank you when you’re not crying over a ruined cookie recipe.
