Why Your Lid Feels ‘Sucked In’—and What to Do About It

Heat sealed vacuum

Here’s what’s happening:

You place hot food inside the dish and seal it with the lid.
The air inside is heated and expands slightly, pushing out some air.
As the food and air cool down, the air contracts, creating lower pressure inside the container.
The outside air pressure (higher) pushes down on the lid, making it feel “sucked in” and hard to remove.

This is basically a mini version of the principle behind how vacuum-sealing works.

Why it’s more noticeable in your dish:

Your lid seals tightly with the silicone gasket, making it pretty airtight.
The double-wall insulation traps heat, so the cooling process is gradual, exaggerating the pressure differential.
No vent means pressure can’t equalize on its own.

How to fix or manage it: