It seems like I have to learn things the hard way. When I try new techniques I read up on them on the forum, do them "my own way" and then after four or five "failures" end up figuring out what people were talking about. The failures are always edible, but they're not really what I'm going for.
I've mostly aged using natural rinds, but I wanted to get better control in aging some cheeses, so I tried my hand at vacuum sealing. I had whey pool up in bags within a week of bagging. I figured I could just let this go. That was mistake number 2. Mistake number 1 was not adequately sterilizing my equipment. I thought I was doing "good enough," and while it may have been for bacteria, it wasn't good enough for yeasts.
I had two provolones and one cheddar with whey in the bag that fermented. It smelled very yeasty (couldn't tell if it was more like a brewer's or baker's yeast, but it doesn't matter). The cheeses had a softer texture that I associate more with blues. They are pretty good on pizza or lasagna.
I've got one provolone in progress that's not bagged yet. I didn't sanitize that one any better (because I made it prior to my epiphany), but hopefully if I dry it out longer before bagging it won't ferment on me.