How can you tell when these have gone bad and are no longer safe for consumption?
If I find some leftover "smooth" cheese like cheddar in the refrigerator that has a small portion with mold growing on it, I'll discard that section and use the rest. But sometimes certain cheeses I just bought at the store will even look suspect. I guess I figure it's okay, and I'm still alive so I guess I made the right call.
Where it's tricky is when it's been in the fridge a week or longer and I see "stuff" on it. It's hard to describe, but it could just look like white powder or something. If it's "fuzz" I assume that's bad and I shouldn't eat it. But what about if it's just little white spots or kind of powdery in appearance?
I have some Stilton in the fridge now and it's got so much stuff going on it's really hard to know. But I've only had it about a week.
As a general matter, I do take care and try to serve only the approximate amount I expect to be consumed in one sitting, thereby keeping any excess cheese refrigerated. Still, it's tricky!