Expert: James Yee - 8/14/2010

Question
QUESTION: I purchased a small humidor last year, a nice little box, nothing fancy.  Lately
I've noticed the white "bloom" that are on some cigars is also starting to get
on (and probably in) the humidifier itself.  Under the humidifier where it
attaches to the box the wood has a few green marks (discolouration of the
wood itself).  It does not appear to be mould, it truly does seem to be bloom
or a mineral trace on the humidifier, but I'm concerned nonetheless about it.  
I've used nothing but distilled water, and (hopefully) prepared the humidor
correctly.  Basically, I'm wondering what is the best way to clean the
humidifier itself and the area under the humidifier, and if I should be taking
any other precautions.

ANSWER: Hi Trevor,

The best way to differentiate mold from mineral trace or bloom is by examining the substance up close with a microscope or magnifying glass.  When examined closely, mold will have a mushroom cap-like head and a long tubular body.  Bloom will appear stringy/dust like and mineral trace will have a chalky, powdery and/or flaky appearance.

Even though you use distilled water, mineral trace can still appear in your humidor and slowly collect over time.

If you are using an foam-based humidifier and the mineral trace has appeared on the porous foam, you can clean the element simply by thoroughly rinsing the foam with distilled water.  If the substance is mold and has appeared on the foam, you should replace the humidifier altogether.  Once mold has embedded itself into the porous foam, it is extremely hard to fully purge it.

If the substance is mold and you wish to clean it, soak the foam element in a small dish of Isopropyl alcohol for one minute and then thoroughly rinse the foam with distilled water.  If mold has appeared on the humidor wood interior, thoroughly vacuum the humidor interior (use a soft-bristle attachment to prevent wood damage) and then wipe the interior down with some Isopropyl alcohol.  Let the humidor sit for 1 minute before re-wiping the interior with distilled water.

After your humidor and humidifier has been cleaned, simply make sure that your hygrometer is calibrated and accurate and that the humidity level does not exceed 75% humidity.  To reduce the chance of mineral trace/lime scale appearing, use 100% distilled water or bidest water (double distilled water).

I hope this helps!  If you have any more questions, please feel free to just ask and I will be happy to help.

Regards,
James

---------- FOLLOW-UP ----------

QUESTION: Most people say not to go above 75% humidity and that 70% is where to shoot
for.  When I first put in my humidifier after refilling it, I find that the humidity
spikes upwards of 85%.  After a few days it's generally levelled off about 75%
and settles in there.  Could this original high humidity be the cause of the
problems and is there something simple I could be doing like letting the
humidifier dry out a bit after re-soaking it?

Answer
Hi Trevor,

True, it's always best to keep your humidor's humidity level close to 70%.  67-73% is acceptable while 70% is considered ideal.  If the humidity is kept at 75% or higher, cigar mold can form.

What you can do is add a 50/50 mixture of distilled water and Propylene Glycol (PG) to your humidifier and this will automatically maintain 70% humidity.  What happens is that the Propylene Glycol will form a protective layer over the humidifier element and this restricts the amount of humidity created to exactly 70% humidity.  PG can last a long time in your humidor (on average, 2 years) so you only need to add it once.  Afterwards, simply add distilled water as you normally would; whenever needed.  (Important: Propylene Glycol may cause the humidity to dip and peak wildly for week after you've added it to your humidor.  If this is the case, just be patient.)

Propylene Glycol can be purchased at most tobacconists, pharmacies and drug stores.  You can even purchase it through the Internet.  Cigar stores will also sell pre-mixed 50/50 humidor solutions but I find it's always handy to have a small bottle of Propylene Glycol just in case you may need to fine-tune the mixture.  A 50/50 mixture should create exactly 70% humidity but if the humidity level is still too high by a few percent, just add a few small drops of PG to balance it out.  If the humidity level is too low after adding the 50/50 mixture, add more distilled water to dilute it.

As an alternative, you may want to consider upgrading to an electronic cigar humidifier such as a Cigar Oasis that allows you to custom set your desired humidity level.  Once set, the humidifier will maintain the humidity level automatically and not exceed it.

Hope this helps.  As always, if you have any more questions, please feel free to just ask.

Regards,
James