Activated Charcoal Powder (also called "ash") is a food-grade charcoal that will neutralize your cheese's surface to create an ideal environment for the ripening and grown of molds such as penicillium candidum and others, while preventing unwanted molds from growing. Mix with salt before applying to the cheese at a 1:5 to 1:8 charcoal to salt ratio depending on the intended ash surface you're after.
* Store in a cool, dry location to preserve indefinitely.