It’s not mold, it’s calcium lactate (2018)

Also, if you get bright white(!) spots on cheese like Brie (which is made with white fungus), it's usually just the cheese "reactivating". You - theoretically - don't even need to cut off anything.

I’ve eaten brie weeks after sell by date. It just turns into a firmer cheese by then no striking difference in taste really.

Yeah, not much seems to happen to Brie - it stays fairly mild. Unlike Camembert, which gets significantly stronger and runnier over time.

I remember having a brie-like cheese cut in half and left forgotten in the fridge for more than a month. The mold had reformed completely, as if it they were made like this in the first place.

It tasted fine, no one got sick. Kind of underwhelming to be honest, but it wasn't particularly tasty to begin with: industrial cheese, pasteurized milk. It fact, that it still had some life in it surprised me.

Fun! I've never let it come that far. Was it somehow fuzzy or really like the firm, white skin that it has when you buy it?

It depends on the Brie - pasteurized or not, from Meaux/Melun/etc. I find Unpasteurized Brie de Melun to be very strong.

> It just turns into a firmer cheese by then

Really? I thought it was the other way around, starting relatively firm and liquefying as it rots.