Q: What types of mold affect premium cigars?
A: The two most common types of mold are “plume” (or “bloom”), and greenish-blue mold. Plume/bloom is evidenced by powdery white spots. These are caused by the oils that are excreted as the wrapper leaf ripens- usually when your cigars are exposed to slightly higher than optimum temperature and humidity levels. Basically, it’s pretty harmless, and it can easily be removed by brushing it off with your finger.
Greenish-blue mold is…well…your typical nasty mold, and not a very good sign; you can also smell it. If you discover this on your cigars, that’s when you get that icky feeling in your stomach telling you your valuable stash may be ruined. That said, if only a very small amount of green/blue mold is on the wrapper, the cigars may still be good enough to smoke. But if the mold is found at the foot of the cigar, toss it. They will only get worse and ruin the other cigars.
If you find a lot of the latter type of mold, all of the cigars should be removed from the humidor immediately and carefully inspected. In the meantime, keep the “good: cigars in a baggie while you clean out the humidor and re-season it.