Camemberts have been pretty reliable for me up until now.
I started my latest batch early in November so that they would be ready for Christmas. After eight days, with no sign of PC growth, I decided to do something so I sprayed with more PC. Two days later and wild moulds were starting to appear.
I decided the only way to salvage something was to change tack and start washing the rind. After four days of washing, a few small patches of PC put in a belated appearance, only to be wiped out by the wash.
The result, about seven or eight weeks after I started, are some very nice washed rind cheeses which I think of as the Phoenixes.
I still don't know why the PC didn't grow. That has never happened to me before and the only thing I did differently was to double the size of the batch. Still, what I ended up with is pretty satisfying.