If I take a warm unopened aluminum can of Coca-Cola and place it in the freezer and let the Coca-Cola freeze solid, then take the can out of the freezer and let it thaw unopened in a typical room, the lid of the aluminum can will invert and be pushed upwards as much as approximately one inch above the normal height of a can.
The can does not open. It just expands. If I let the Coca-Cola thaw out sufficiently, but not entirely, no Coca-Cola will bubble out of the can when I open it and I hear no gas escaping either.
I am confused by the force exerted by thawing Coca-Cola. What is going on? Why does the force disappear while much of the Coca-Cola is still frozen?
I caution anyone from repeating this 'experiment' because I am concerned the can could explode.
I have experienced expanding cans of Coca-Cola repeatedly because I like to drink Coca-Cola at near freezing temperature. At work I only have access to a refrigerator / freezer, but no ice. So, I frequently place a can of Coca-Cola in the freezer. Sometimes I forget the can is in the freezer and the Coca-Cola freezes solid. Only once has the can opened in the freezer itself I guess by 'exploding'.
Here is a related question, but it only addresses changes in sweetness as Coca-Cola thaws, not forces presumably caused by expanding gases.
Best Answer
Adding to your hypothesis, perhaps restating it, freezing forces carbon dioxide out of the liquid, which creates pockets of highly compressed gas. As the can warms, the gas begins to expand faster than it is reabsorbed into the liquid. If the integrity of the can remains intact, the gas will be reabsorbed, re-dissolved into the liquid. In my freezer, Cokes never survive that long.
Now ... that said, I have some pricey Belgian ales that are bottled in heavy 750ml bottles & corked with wire cages to hold the cork in. I have had at least one force a minute amount of liquid, presumably some gas too, past the cork before the bottle froze solid. When the beer thawed back to drinking temperature in the fridge, over a day or two, the beer was quite bubbly & tasty.