Can I freeze soup in a pot (I believe it's made of stainless steel)? Are there any health risks? Is there any risk of damage to the pot?
The possible risks I can think of are (1) the large thermal mass may mean that the soup cools off too slowly, leading to spoilage in the middle, and (2) freezer burn on the top of the soup, because there's no truly effective way to seal out air from a pot. In practice, (1) is unlikely unless you're talking about a 25-gallon pot or something, in which case it wouldn't fit in an ordinary freezer anyway. (2) on the other hand will be a problem, unless you're only freezing the soup for a short period.
The only risk to the pot is that it may not quite fit in the freezer comfortably, so as people take things out and put things in, they may shove the pot about and maybe break a handle or something.
There are no health safety risks with storing food in a stainless steel, or most other cooking pot metals for that mater
The pot should be fine, but there is always a risk with metal in a freezer in that bare skin contact may freeze to it. Also other products in freezer bags may even freeze to it
In general it's easier not to use metal containers in the freezer, unless enamelled or plastic coated
Water expands when it freezes. That has a small risk of damaging the pot (though, it'll likely expand upwards instead—do not fill to the top). E.g., this can cause glass jars to break. Metal is more flexible though (and you have a very wide "mouth" on the pot).
But I'm unsure why you'd ever want to do this.
Freezing in disposable hot-beverage cups (the non-styrofoam type that coffee is served in) is a much better option. First, its a single serving per cup, so you can easily pull one serving out of the freezer. Second, they're microwavable.
To freeze in disposable cup:
- Ladle soup into cup
- Once cooled to reasonable temperature (say, 140°F), place piece of plastic wrap over top, pressed down over soup to remove all air
- Put lid on (which will hold down the plastic wrap).