Maybe this is a silly question, but I'm not quite sure.
Consider a solid yogurt. Can we assign a specific state of matter to it?
I mean, it behaves like solid. However, if we "mix" it with a spoon, it becomes liquid, or at least in the usual sense. It is also quite plastic, which complicates.
My current guess is that it is either a glass or a gel, but I'm quite unsure about it.