dumped flour in it. I've never had anything like that - is that normal sometimes, depending on certain factors? It was Buttermilk brand. I hope that's ok to say.) It tastes fine, just a wierd texture.
I like buttermilk cheeses but find that they tend to be grainy sometimes.
So it might be normal. There is a local cheesemaker that makes a buttermilk 'cheddar' and it's wonderful but grain and has some of the characteristics of good parm.
Usually I can tell if it's gone bad because it gets 'slimy' - doesn't look a lot different but feels different. I freeze blue cheese all the time though - both in chunks and crumbles. I buy the big wedge at Costco and keep some in the freezer for quick Buffalo Chicken Dip.