[s1artibartfast]

100% relative humidity is ~23 grams/m^3 at 25C

That is <6 grams if you sucked every molecule out of 0.25 m^3.

Air at 0 C still has about 5 grams/m^3, so the number would actually be lower.

50% RH at 25C to 100% RH at 0 would condense ~1.6 grams of water from the air .

To hit 10g you need 45+ grams per m^3, which would be 100% humidity at >37C (eg, the tropics)

[londons_explore]

Think of an ice cold beer sitting out. Quite quickly it gets covered in dew.

But the inside of your fridge and all the goods inside has the surface area of hundreds of ice cold beers.

It isn't just a matter of how much room air you trapped in the fridge, but how much passes the beers in the fridge while you have the door open - perhaps 10x as much.