Certain sorts of mold produce compounds called mycotoxins, which considered toxic to humans. These mold spores can grow on foods thanks to spoilage. But they’re typically fuzzy and white, green, black, blue, or grey. However, unlike these sorts of mold, the sorts of Penicillium wont to produce blue don’t produce toxins. And considered safe to consume. During the cheesemaking process, Penicillium added after the curds drained and rolled into wheels. The blue then left to age for 2–3 months before it’s able to enjoy.