I made a mesophilic MC about a month ago. I froze a chunk of it in cubes and used a chunk fresh. I am trying to use the frozen culture for the first time to make creme fraiche and now at about 18 hours since inoculating 1/2 L of cream with 2 oz frozen MC I see no coagulation.
I assume this means my frozen culture is dead, but what might have caused this? I froze and quickly transferred cubes to a plastic bag.