An unopened bag of chocolate chips which I had placed in my fridge several weeks ago has expanded as if inflated with gas.

This has never before happened with any other bags of chocolate chips.
A can of soda water did however expand yesterday... I assume it got too cold and partially froze. Why would being too cold make a bag of chocolate expand, though?
The bag remains inflated even after having taken it out of the fridge. I shall open the bag to see what lies inside...
Looks like chocolate. Tastes like chocolate.

This has never before happened with any other bags of chocolate chips.
A can of soda water did however expand yesterday... I assume it got too cold and partially froze. Why would being too cold make a bag of chocolate expand, though?
The bag remains inflated even after having taken it out of the fridge. I shall open the bag to see what lies inside...
Looks like chocolate. Tastes like chocolate.