For any cigar smoker, few things are more worrying than opening a humidor and spotting white or coloured spots on a cigar. Is it plume (also called bloom) — a sign of fine ageing — or is it mold, which can ruin a cigar and even spread through your collection?
Knowing the difference is essential for protecting your investment and enjoying your cigars at their best.
What Is Plume (Bloom)?
- Appearance: Fine, powdery, greyish-white crystals that sit on the surface of the wrapper.
- Texture: Dust-like and disappears when gently brushed away.
- Cause: Natural oils secreted from the tobacco during the ageing process, which crystallise over time.
- Significance: Plume is harmless and often considered a badge of honour. It indicates that the cigar has been stored well and has matured beautifully. Many aficionados even hope to see plume on their long-aged Havanas.
What Is Mold?
- Appearance: Greenish, bluish, or greyish spots. Mold can look fuzzy, furry, or patchy.
- Texture: Unlike plume, mold does not brush away easily. It may leave a stain behind when scraped off.
- Cause: Excess humidity or poor air circulation inside the humidor.
- Significance: Mold is damaging, spreads quickly, and can ruin cigars and even the humidor itself.
Key Differences Between Plume and Mold
- Colour: Plume is white or greyish-white; mold is often green, blue, or grey.
- Removal: Plume brushes off cleanly; mold leaves stains.
- Texture: Plume looks like a fine powder; mold appears fuzzy or furry.
- Impact: Plume is harmless; mold can destroy cigars and needs urgent attention.
Rule of Thumb:
- Dusty and crystalline? → Plume
- Spotty, fuzzy, or coloured? → Mold
What to Do If You Find Plume
If you’re lucky enough to find plume:
- Gently brush it away before smoking.
- Admire the cigar’s age and maturity.
- Enjoy — it’s a sign you’ve been storing your cigars correctly.
What to Do If You Find Mold
- Isolate affected cigars immediately to prevent spreading.
- Inspect carefully: if only the wrapper is affected, some cigars may be salvageable; if mold has penetrated the foot or filler, discard them.
- Clean your humidor:
- Remove all cigars.
- Wipe the interior with a cloth lightly dampened with isopropyl alcohol.
- Allow the humidor to air out for at least 24 hours.
- Re-season and re-humidify before reintroducing cigars.
- Check humidity and temperature: keep levels around 65–68% humidity and 16–18°C to prevent recurrence.
Final Puff
Bloom (plume) is a welcome sign of a cigar that has aged gracefully, while mold is an unwelcome problem caused by excess humidity. The difference is usually clear: plume is dusty, white, and harmless, while mold is fuzzy, coloured, and destructive.
If you’re ever in doubt, consult a trusted tobacconist — better to be safe than to risk your prized collection.
Explore our range of humidors and cigar care accessories to keep your cigars ageing perfectly and free from mold.