I came across a site today with an interesting Gorgozola recipe, but there was a comment on there about Penicillium candidum and P. roqueforti needing to be rehydrated 24 hours before use--and not to spray on the cheese, but to add it to the milk. I've used both before and never rehydrated either. How necessary is the rehydration then? And what's the difference if it is rehydrated?