I opened a jar of heavy cream pasta sauce (pumpkin, tomato, cream, etc), ate some and stored the rest in the fridge. The next day it seamed to have sealed itself. The button stayed down when I happened to press it. When I opened it the second time it popped loud. Like new.
Why did this happen? Is it safe to eat? The sauce was store bought. Thank you.:)
Additional info added by OP (in a now-deleted answer):
I put it into the fridge within 20 minutes. But it was room temperature when it went in the fridge. I didn’t heat it at all and it wasn’t especially hot weather.
I asked because sealing seems significant. And it resealed itself with no action on my part. Should I check my refrigerator? Could a jar reseal on its own happen if the fridge temp was unstable? (The power didn’t go out but it's possible it could have been finicky in the storm overnight.)