Here’s the part where life gets tricky. Cut onions are a whole different beast. If you chop half an onion for tacos and leave the other half on the counter, that half will start a tiny civilization of mold within 24 hours. You’ll find it, grimace, and wonder if you can just scrape it off (spoiler: you can’t).
So yes, cut onions belong in the fridge, sealed in an airtight container or a ziplock bag. Think of it as putting a leftover slice of pizza to bed—it’s not ideal, but it’s the only way to keep it from becoming a science project.
How long do they last in there?
A cut onion in the fridge will stay decent for about 7 to 10 days, but honestly, the flavor starts to fade after day three. It becomes a ghost of its former self—mild, slightly watery, and a little sad. It’s the produce equivalent of a friend who says they’re “fine” but you know they’re not.
I once kept a half-onion in the fridge for two weeks, thinking I’d use it for soup. When I finally opened the bag, it smelled like a forgotten gym sock that had made friends with a skunk. I threw it out and ordered pizza. Don’t be like me.
