Mold vs. Plume on Cigars: How to Tell the Difference
For many cigar enthusiasts, few topics create as much confusion as the difference between mold and plume (also known as “bloom”). At first glance, they may look similar—but they carry very different implications for the quality, safety, and enjoyment of your cigars.
Mold on Cigars
Appearance:
Mold shows up as fuzzy or powdery patches on the wrapper. It can be white, green, blue, or even black.
Texture & Smell:
If you run your finger across it, mold smears, feels slimy, and is often accompanied by a musty odor.
Cause:
Mold thrives in humidors where conditions get out of balance—typically when humidity rises above 70% RH or when airflow is poor. Higher temperatures accelerate the problem.
Health & Smokeability:
Mold is harmful if inhaled or ingested, and once it penetrates a cigar, the cigar is ruined. While surface mold can sometimes be wiped away, it’s a gamble—internal contamination means it’s best to discard the cigar.
Remedy:
- Immediately remove any affected cigars.
- Deep-clean the humidor before restocking.
- Recalibrate your hygrometer and ensure humidity stays in the 65–69% RH range.
Plume (Bloom) on Cigars
Appearance:
Plume looks like a fine, powdery frost—a thin layer of white crystals evenly coating the wrapper.
Texture:
Unlike mold, plume is neither fuzzy nor slimy. Gently rubbing it makes it disappear or spread evenly across the surface.
Cause:
Plume develops naturally when the oils in well-aged tobacco migrate to the surface and crystallize under stable conditions.
Quality Indicator:
Far from being a flaw, plume is celebrated by collectors and aficionados as a marker of maturity and refined storage. It can even add nuance to the flavor of a properly aged cigar.
Mold vs. Plume: Quick Guide
| Feature | Mold | Plume (Bloom) |
|---|---|---|
| Color | White, green, blue, black | White only |
| Texture | Fuzzy, smears, slimy | Powdery, crystalline, disappears when rubbed |
| Odor | Musty, unpleasant | Neutral |
| Impact | Unsafe, ruins cigar | Harmless, often desirable |
Final Thoughts
The distinction is simple but essential:
- Mold = a problem. Caused by excess humidity, unsafe to smoke, requires immediate action.
- Plume = a blessing. A natural byproduct of slow, careful aging that enhances your cigars’ pedigree.
The best defense against mold—and the best chance of seeing plume—is consistent, precise storage. Keep your humidor in balance, inspect your cigars regularly, and you’ll not only protect your collection but also appreciate the natural artistry of cigar aging.